Ultrasonic cleaner and automatic analyzer using the same

ABSTRACT

An ultrasonic cleaner according to the present invention includes a vibrating part 222 for enlarging ultrasonic vibration of a bolt-clamped Langevin type transducer (BLT) 100 on a side surface side in a cleaning tank 211, generates cavitation by the ultrasonic vibration with respect to cleaning liquid supplied into the cleaning tank 211 by driving the BLT 100 on the periphery of a nozzle without unevenness, and is capable of performing effective nozzle cleaning.

TECHNICAL FIELD

The present invention relates to an ultrasonic cleaner for cleaning anozzle which suctions a sample or a reagent in an automatic analyzerwhich performs component analysis or the like by mixing the sample, suchas serum or urine, with the reagent.

BACKGROUND ART

In an automatic analyzer, in order to dispense a sample by repeatedlyusing the same nozzle, a nozzle tip end is cleaned before suctioning adifferent sample. When the nozzle tip end is not sufficiently cleaned,the previous sample component is carried over the next sample, andmeasurement accuracy deteriorates (carry-over). Meanwhile, in theautomatic analyzer having high throughput performance, since dispensingprocessing is performed at high speed, sufficient time is not taken toclean the nozzle. As a more effective method of cleaning the nozzle, inPTL 1, a method of removing contaminants (residual of the previoussample) which adhere to the nozzle due to cavitation occurred in liquid,by using an ultrasonic cleaner in which a bolt-clamped Langevin typevibrator (hereinafter, referred to as a bolt-clamped Langevin typetransducer (BLT)) is provided at a bottom part of a cleaning tank, isdisclosed.

In addition, in PTL 2, as an ultrasonic cleaner for a nozzle, aconfiguration in which an ultrasonic wave is converged in a nozzle bydisposing a plurality of piezoelectric elements (vibrator array) in acylindrical cleaning tank, is disclosed.

CITATION LIST Patent Literature

PTL 1: JP-A-4-169850

PTL 2: JP-A-2010-133727

SUMMARY OF INVENTION Technical Problem

In performing the cleaning using the ultrasonic wave, the obtainedcleaning actions vary according to a frequency band (low frequency,intermediate frequency, high frequency) which is generally used indriving an ultrasonic vibrator, and the low frequency (20 to 100 kHz) isused with respect to the contaminants which are unlikely to be removed.At the low frequency, cavitation (a phenomenon in which bubbles aregenerated or extinguished due to a pressure difference generated in theliquid) which occurs in the liquid is used. An occurrence condition ofthe cavitation includes a threshold value of the ultrasonic intensitywhich varies according to the driving frequency, stronger cavitation isobtained as the ultrasonic intensity increases, and a cleaning effectincreases. In addition, regarding the threshold value of the ultrasonicintensity for the occurrence of the cavitation, since it is necessary togenerate a strong ultrasonic wave as a driving frequency increases, thecavitation is hardly generated in the method which uses the highfrequency. Furthermore, the cavitation does not occur equivalently inthe liquid, and the strength of the cavitation also changes according tothe degree of the ultrasonic intensity. A region in which the ultrasonicintensity increases can be a region in which the generated intervalvaries according to the driving frequency, and the cavitation becomesstronger for each distance obtained by dividing the sound velocity(approximately 1500 m/s in water) of the liquid by the driving frequencyof the ultrasonic vibrator. For example, when the driving is performedat 50 kHz, a region in which a standing wave in which one wavelength is30 mm is generated, and the cavitation strength is strong at an intervalof 15 mm which is a half-wavelength of the wavelength of the standingwave, is generated.

For example, in the ultrasonic cleaner in which the BLT is provided at alower part of the cleaning tank as described in PTL 1, the driving isperformed at 20 to 100 kHz in order to obtain the effect of cavitation,but the region in which the cavitation becomes strong is generated at aninterval of 7.5 mm (driving at 100 kHz) to 37.5 mm (driving at 20 kHz).The cavitation strength increases when being close to the BLT which is adriving source. In addition, a range of the region in which thecavitation strength increases is narrow. Due to this, a cleaning rangeof the nozzle is restricted and cleaning unevenness is likely to occur.

In addition, in PTL 2, a cleaning mechanism in which a plurality ofultrasonic arrays that generate the ultrasonic wave are disposed to bealigned in the circumferential direction and in the shaft direction of adispensing nozzle on the inside of the cleaning tank, is disclosed.According to the configuration, the problem regarding the cleaningunevenness can be comparatively solved. However, it is difficult toobtain a high cleaning effect in the ultrasonic array.

The strength of the cavitation mainly depends on amplitude of avibrating member. In other words, as the amplitude of the vibratingmember increases, the strength of the cavitation increases. Theultrasonic array described above is considered, for example, an arraywhich uses the piezoelectric element, but as described above, in a casewhere the piezoelectric element becomes the vibrating member, it is notpossible to expect a substantially large amplitude since the deformationitself of the piezoelectric element is used.

In addition, as described above, the cavitation can effectively occur atthe low frequency (20 to 100 kHz), but a resonance frequency of a singlepiezoelectric element is several MHz, and in a case where the driving isperformed at the low frequency (20 to 100 kHz), a deformation amountcannot be effectively obtained. Meanwhile, when large voltage isexcessively applied to the piezoelectric element in order to increasethe deformation amount, the element itself becomes broken. Therefore, inorder to obtain a high cleaning effect, it is not appropriate to allowthe piezoelectric element itself to be a vibrating member.

As described above, in the ultrasonic cleaner for cleaning the nozzle,it is difficult to obtain a high cleaning effect while suppressing thecleaning unevenness.

Here, an object of the present invention is to provide an automaticanalyzer or the like provided with the ultrasonic cleaner for the nozzlethat can obtain a high cleaning effect while suppressing the cleaningunevenness.

Solution to Problem

The following is a representative invention.

According to the representative invention, there is provided anautomatic analyzer including: a nozzle which suctions a sample or areagent; a cleaning tank which cleans the nozzle; an ultrasonic cleanerwhich generates an ultrasonic wave; and a control portion which performsdriving control of the ultrasonic cleaner, in which the ultrasoniccleaner includes a vibrating part which is inserted into cleaning liquidin the cleaning tank, and transmits ultrasonic vibration to the cleaningliquid, and an ultrasonic vibrator which is configured by fixing andfastening a piezoelectric element with two or more metal blocks by abolt, and generates the ultrasonic vibration to the vibrating part, andin which the control portion causes the vibrating part to generate theultrasonic vibration to clean the nozzle.

In addition, according to another representative invention, there isprovided an ultrasonic cleaner including: a vibrating part which isinserted into cleaning liquid in a cleaning tank, and transmitsultrasonic vibration to the cleaning liquid; an ultrasonic vibratorwhich is configured by fixing and fastening a piezoelectric element withtwo or more metal blocks by a bolt, and generates the ultrasonicvibration to the vibrating part; and a control portion which performsdriving control of the ultrasonic vibrator, in which the control portioncauses the vibrating part to generate the ultrasonic vibration to cleana nozzle which suctions a sample or a reagent.

In addition, according to still another representative invention, thereis provided an ultrasonic cleaner including: a cleaning tank which hasan insertion port of a nozzle at an upper part thereof, and is capableof storing liquid on the inside thereof; a vibrating part which isprovided on a side surface side in the cleaning tank; and an ultrasonicvibrator which is connected to the vibrating part, in which theultrasonic vibrator vibrates the vibrating part in the horizontaldirection, and in which the nozzle is cleaned based on the vibration ofthe vibrating part.

In the ultrasonic cleaner of the present invention, it is possible togenerate strong cavitation with respect to the liquid in the cleaningtank according to the ultrasonic vibration enlarged by the vibratingpart, and to give the ultrasonic vibration from the side with respect tothe nozzle inserted from the opening part of the upper part of thecleaning tank by further providing the vibrating part on a side surfaceside.

Here, the vibrating part provided on the side surface side in thecleaning tank is not provided on the side surface itself of the cleaningtank, but is provided on the side surface side using the dispensingnozzle inserted into the insertion port as a reference. In other words,both a case where the vibrating part is provided on the side surfaceitself of the cleaning tank and a case where the vibrating part isinserted into the cleaning tank, are included. In addition, the sidesurface is a term which is used for distinguishing the bottom surface,and the side surface mentioned in the specification is a term whichmeans the side surface among the side surface and the bottom surface,and does not include the bottom surface. In addition, the side surfaceside is also a term which is used for distinguishing the bottom surfaceside.

Advantageous Effects of Invention

According to the present invention, it is possible to provide anautomatic analyzer or the like provided with an ultrasonic cleaner for anozzle which can obtain a high cleaning effect without cleaningunevenness.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an upper view of an automatic analyzer provided with anultrasonic cleaner of Example 1.

FIGS. 2(a)-2(d) are appearance views of an example of the ultrasoniccleaner of Example 1.

FIGS. 3 (a)-3 (b) are appearance views of an example of the ultrasoniccleaner of Example 1.

FIGS. 4(a)-4(c) are an example of ultrasonic vibration means of Example1.

FIGS. 5(a)-5(b) are a view illustrating a standing wave generated whenapplying an ultrasonic wave in the liquid.

FIGS. 6(a)-6(b) are views illustrating a relationship of cleaning liquidand a nozzle position in the ultrasonic cleaner of Example 1.

FIG. 7 is a view illustrating an example of a pipe configuration in theultrasonic cleaner of Example 1.

FIG. 8 is an example of a processing flow of nozzle cleaning in whichthe ultrasonic cleaner of Example 1 is used.

FIGS. 9(a)-9(b) are appearance views of an example of the ultrasoniccleaner of Example 1.

FIGS. 10(a)-10(c) are appearance views of an example of an ultrasoniccleaner of Example 2,

FIGS. 11(a)-11(d) are appearance views of an example of an ultrasoniccleaner of Example 3.

FIGS. 12(a)-12(e) are appearance views of an example of an ultrasoniccleaner of Example 4.

FIGS. 13(a)-13(d) are appearance views of an example of the ultrasoniccleaner of Example 4.

FIG. 14 is an example of a liquid overflow structure and pipe connectionin the ultrasonic cleaner of Example 4.

FIGS. 15(a)-15(c) are examples of a cleaning flow and a time chart inwhich the ultrasonic cleaner of Example 4 is used.

FIG. 16 is an example of a temperature abnormality detection flow in theultrasonic cleaner of Example 4.

FIGS. 17(a)-17(d) are configuration examples of an ultrasonic cleaner ofExample 5.

FIGS. 18(a)-18(h) are examples of a structure of a vibrating part(cleaning pad) of the ultrasonic cleaner of Example 5.

FIGS. 19(a)-19(d) are views illustrating an example of a vibration modeof the cleaning pad and a temperature gradient of the cleaning liquid,in Example 5.

FIG. 20 is an example of the time chart of the nozzle cleaning in whichthe ultrasonic cleaner of Example 5 is used.

FIG. 21 is a configuration example of a dispensing mechanism of anautomatic analyzer and a control block of the cleaner in Example 5.

FIG. 22 is an example of the cleaning flow in which the ultrasoniccleaner of Example 5 is used.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described indetail with reference to FIGS. 1 to 22.

Example 1

FIG. 1 is a view illustrating a configuration of an automatic analyzerof the present invention. An automatic analyzer 10 is configured of areagent disk 12 on which a plurality of reagent containers 11, areaction disk 13 which has a reaction cell in which a mixture of areagent and a sample (hereinafter, referred to as a sample) isaccommodated, a reagent dispensing mechanism 14 which suctions andejects the reagent, and a sample dispensing mechanism 15 which suctionsand ejects the sample.

The reagent dispensing mechanism 14 is provided with a reagent nozzle 21for dispensing the reagent, and the sample dispensing mechanism 15 isprovided with a sample nozzle 22 (hereinafter, referred to as a nozzle22) for dispensing the sample. The sample put into the device is loadedon a lack 24 and is transported in a state of being in a samplecontainer (test tube) 23. The plurality of sample containers 23 areloaded on the lack 24. In addition, the sample is a sample from blood,such as serum or whole blood, or urine.

The sample dispensing mechanism 15 moves the nozzle 22 to a suctionposition at which the sample is suctioned from the sample container 23,an ejection position at which the sample is ejected to a reaction cell25, a cleaning position at which a tip end of the nozzle 22 is cleanedby an ultrasonic cleaner 26 of the present invention, and a cleaningposition at which a cleaning tank 27 which washes the tip end of thenozzle 22 with water is provided. Furthermore, the sample dispensingmechanism 15 lowers the nozzle 22 in accordance with each height of thesample container 23, the reaction cell 25, the ultrasonic cleaner 26,and the cleaning tank 27 at the suction position, the ejection position,and the cleaning position. In order to perform such an operation, thesample dispensing mechanism 15 is configured to rotate the nozzle 22 ateach stop position, and to be vertically movable.

The automatic analyzer has a measuring portion 29, and analyzes aconcentration of a predetermined component in the sample by performingphotometry with respect to the mixture of the sample and the reagentaccommodated in the reaction cell 25. The measuring portion 29 has, forexample, a light source and a photometer, and the photometer is, forexample, a light-absorption photometer or a light-scattering photometer.

In addition, movement of the nozzle 22 or absorption ejection control ofthe sample, control of liquid supply to the cleaning tank 27, drivingcontrol of the ultrasonic cleaner 26, and control of other various typesof mechanisms, are performed by a control portion 28. In addition, asthe automatic analyzer, a device which is provided with an operatingportion (PC or control board) for operating the device, and a unit whichinputs or collects the lack 24 by an examiner is employed, but in FIG.1, the device is omitted.

Next, an analyzing operation of the automatic analyzer will bedescribed. The lack 24 in which the sample container 23 is accommodatedmoves to the suction position of the sample. At this position, thesample is suctioned by the nozzle 22 from the sample container 23. Thesuctioned sample is ejected to the reaction cell 25. The reagent disk 12moves the desired reagent container 11 to a position at which thereagent nozzle 21 can access the reagent container 11 being rotated. Atthis position, the reagent is suctioned by the reagent nozzle 21 fromthe reagent container 11. The suctioned reagent is ejected to thereaction cell 25. The mixture of the sample and the reagent which areaccommodated in the same reaction cell 25 are agitated, and the reactiondisk 13 proceeds the reaction of the sample and the reagent whilerepeating the rotation and stop.

The reaction disk is driven while repeating the rotation and stop, andthe reaction cell 25 which is a target to be measured periodicallypasses through the front of the measuring portion 29. When passing, thelight irradiated from the light source is transmitted through themixture in the reaction cell 25 and scattered to the mixture, andabsorbance and scattering intensity are measured by the photometer. Fromthe information of the light obtained by the photometer, theconcentration of a predetermined component, which corresponds to thetype of the reagent in the sample, is calculated.

Next, the ultrasonic cleaner 26 will be described. After dispensing andcleaning one sample, the nozzle 22 uses the sample repeatedly indispensing. In a case of performing examination of many items withrespect to one sample, the same sample is dispensed to the plurality ofreaction cells 25. Since the dispensing is performed from the samesample, in this case, even after the sample is dispensed, basically, itis not necessary to perform strong cleaning. Therefore, while dispensingthe same sample, basically, it is not necessary to perform the cleaningby the ultrasonic cleaner 26. Meanwhile, in a case where strong cleaningis required, for example, at a timing when the sample to be dispensed isswitched, the cleaning in which the ultrasonic cleaner 26 is used isperformed.

Next, the ultrasonic cleaner will be described. The ultrasonic cleanerincluding a cleaning tank which has an insertion port of the dispensingnozzle at an upper part thereof, and is capable of storing the liquid onthe inside thereof, a vibrating part which is provided on the sidesurface side in the cleaning tank, and an ultrasonic vibrator which isconnected to the vibrating part, and in which the ultrasonic vibratorvibrates the vibrating part in the horizontal direction, will bedescribed hereinafter.

FIG. 2 is an appearance view of an example of the ultrasonic cleaneraccording to the present invention. FIG. 2(a) is a perspective view ofthe ultrasonic cleaner, FIG. 2(b) is an upper view of the ultrasoniccleaner, FIG. 2(c) is a sectional view of the ultrasonic cleaner, andFIG. 2(d) is a perspective view (with a cover) of the ultrasoniccleaner, respectively. FIG. 2 is an example in which a diaphragm 202 isused as a vibrating part.

The ultrasonic cleaner 26 of the embodiment is configured of a BLT 201which vibrates by applying (for example, inputting a sign wave) voltagewhich periodically changes, the diaphragm 202 to which the BLT 201 isattached, a cleaning port 203 which can interpose and fix the diaphragm202, a flange 204, a sealing material 205 for preventing liquid leakagefrom between the cleaning port 203 and the diaphragm 202. The diaphragm202 is fixed so that a circumferential end part is pressed by thecleaning port 203 and the flange 204, and the sealing material 205 has ashape of a doughnut, and is configured to block only the circumferentialend part of the diaphragm 202. A supply port and a discharge port ofcleaning liquid which will be described later are provided in thecleaning port 203, but are omitted in FIG. 2.

In addition, the cleaning port 203 has an opening part 210 (insertionport) for inserting the nozzle 22 to the upper part thereof, and has alarge opening part on the side surface of a cleaning tank 211 in whichthe cleaning liquid is stored, and by blocking the opening part with thediaphragm 202, the cleaning liquid can be stored in the cleaning port203. The vibration generated in a BLT 100 is transmitted to the directlylinked diaphragm 202, and is transmitted to the cleaning liquid in thecleaning tank 211 which is in contact with the diaphragm 202. Accordingto the above-described configuration, when the voltage whichperiodically changes and is equal to or greater than 20 kHz is appliedto the BLT, the ultrasonic wave can be generated in the cleaning liquidin the cleaning tank 211.

Furthermore, in the ultrasonic cleaner 26 of the present invention, thediaphragm 202 which generates the ultrasonic vibration is on the sidesurface of the cleaning tank 211, and can generate the ultrasonic wavefrom the horizontal direction with respect to the nozzle 22 insertedfrom the opening part 210. In addition, it is preferable that theopening part 210 into which the nozzle 22 is inserted has a shape intowhich the nozzle 22 is inserted to a position of the diaphragm 202 asnear as possible (the reason will be described later). Therefore, asillustrated in FIG. 2(a), a part of the opening part protrudes to thediaphragm 202 side, and the part of the opening part 210 and thediaphragm 202 are connected to be adjacent to each other via a part ofthe opening part 210. In other words, a cutout into which the nozzle 22is inserted is provided in the opening part 210, and the thickness of amember of the cleaning port is thin compared to that of other locations.By the configuration, it is possible to perform the cleaning by makingthe nozzle 22 close to the diaphragm 202. In addition, for example, by aconfiguration in which the locations at which the cleaning port is thinas described above is completely removed, and a part of the opening part210 is in contact with the diaphragm, it is possible to perform thecleaning by making the nozzle 22 closer to the diaphragm 202. In otherwords, in the opening part 210 of the cleaning port 203 which interposesthe opening part 210, a state (free end) in which a part of thecircumferential end part of the diaphragm a part of which is open is notpressed, is achieved.

A cover 220 for protecting the BLT 100 may be attached to the ultrasoniccleaner 26.

FIG. 3 is an appearance view of another example of the ultrasoniccleaner of the embodiment. FIG. 3(a) is a perspective view of theultrasonic cleaner, and FIG. 3(b) is a sectional view of the ultrasoniccleaner, respectively. An ultrasonic cleaner 200 (26 in FIG. 1) is notdifferent from the ultrasonic cleaner 26 in the method of use or theinstallation position, except for the shape of the cleaning port 203,the flange 204, and the diaphragm 202 the upper parts of which are cutunlike the ultrasonic cleaner 26.

The ultrasonic cleaner 200 interposes and fixes the diaphragm 202 theupper part of which is cut by the cleaning port 203 and the flange 204,but a side of the upper part is not restrained and becomes a free end.As described above, the diaphragm 202 is configured so that thedeformation amount of the center part increases, but even in thediaphragm 202 of the ultrasonic cleaner 200, the deformation amountincreases in the vicinity similar to the diaphragm 202. However, as oneside of the diaphragm 202 becomes a free end, the deformation amount inthe vicinity of the shaft (center) of the diaphragm 202 can be enlargedto be greater than the deformation amount of the diaphragm 202 the upperpart of which is not cut. In order to obtain a high cleaning effect,similar to the ultrasonic cleaner 200 of FIG. 3, it is preferable to usethe diaphragm 202 at least a part of which is a free end.

In addition, in the ultrasonic cleaner 200, components (pipe connectionor a receiver) which supply and discharge the cleaning liquid are notillustrated, but the cleaning liquid of the cleaning tank 211 isreplaced being overflowed by the pressure of a syringe pump similar tothe ultrasonic cleaner 26. In addition, a lid which prevents thecleaning liquid from being scattered may be provided at the upper partof the cleaning tank 211, and a hole into which the nozzle 22 can beinserted may be provided in the lid.

FIG. 4 is an example of ultrasonic vibration means of the embodiment.FIG. 4(a) is an appearance view in which the diaphragm the upper part ofwhich is not cut in FIG. 2 is attached to the BLT, FIG. 4(b) is a sideview of the diaphragm, and FIG. 4(c) is a perspective view of thediaphragm. The ultrasonic vibration means of the ultrasonic cleaner 26of the invention is configured of the above-described diaphragm 202 andthe BLT 201. The BLT 201 interposes one or more piezo elements 311 by ametal pressing member (on the diaphragm side) 312 and a metal pressingmember (on the free end side) 313. A screw is cut in the pressing member312 and the pressing member 313. The piezo element 311 is a hollow, andby fastening the pressing member 312 and the pressing member 313 by ablot (not illustrated), the piezo element 311 is fixed. Since the BLT201 is a known member, the detailed description of the method of use andthe manufacturing method will be omitted.

The diaphragm 202 is configured of a screw portion 321 for connectingthe BLT 201, a metal plate 322 for transmitting the vibration from theBLT 201, a vibrating part 323 for transmitting the vibration to thecleaning tank, and a neck 324 for amplifying displacement from the BLT201. The connection between the diaphragm 202 and the BLT 201 isfastened by the screw portion (male) 321 of the diaphragm 202 and thescrew portion (female) of the metal pressing member 312. The metal plate322 is in contact with the metal portion 312 for transmitting thevibration from the BLT 201. As described above, in the vibrating part323, the circumferential end part of the vibrating part 323 is fixed tobe interposed by the cleaning port 203 and the flange 204, and the BLT100 is fixed (a side opposite to the diaphragm 202 is free) to thediaphragm 202 in a cantilevered state. The diaphragm 202 is fixed at thecircumferential end part, and the displacement of the free BLT 201 onone side which is at the center acts on the fixed side of thecircumferential end part. Therefore, in the example illustrated in FIG.4, from the end part of the neck 324, in the diaphragm 202, thedeformation amount increases as the distance to the fixed sideincreases. In other words, the deformation amount increases as a part ofthe neck 324 becomes narrow. For example, in a case where the metalportion 312 of the BLT 201 is configured to directly come into contactwith the vibrating part 323, the distance from the end part of the BLT201 to the fixed side of the diaphragm 202 becomes short, and thus, thedisplacement amount cannot be obtained compared to the configurationillustrated in FIG. 4.

Since the BLT 201 vibrates by applying the voltage which periodicallychanges to an electrode (not illustrated) at the front and rear part ofthe piezo element 311, a dedicated power source amplifier (notillustrated) is necessary. In the automatic analyzer, it is possible todrive the ultrasonic cleaner 26 by a command from a CPU board (notillustrated) which controls the device to the power source amplifier.

FIG. 5 is a view illustrating a standing wave generated when theultrasonic wave is applied to the liquid. FIG. 5(a) illustrates thestanding wave when the frequency of the ultrasonic vibration is low, andFIG. 5(b) illustrates the standing wave when the frequency is high,respectively. When the ultrasonic vibration is generated by anultrasonic vibrating part 400, a standing wave 401 of the ultrasonicwave is generated in the liquid. The wavelength of the standing wavevaries according to the frequency of the ultrasonic vibration, and thewavelength becomes long as the frequency becomes low. Therefore, in ahalf-wavelength 402 of the standing wave, 402 a is longer than 402 b. Asdescribed above, the cavitation which has a cleaning effect occurs at apart having high ultrasonic intensity, and the ultrasonic intensityincreases in a region 403 a in the vicinity of a surface of theultrasonic vibrating part 400, and in a region 404 a which is thehalf-wavelength 402 away from the ultrasonic vibrating part 400. Thedistance of a region 403 and a region 404 can be shortened by changingthe frequency, but the distance cannot be set to be 0 at the frequency(approximately equal to or less than 100 kHz) at which the cavitation islikely to occur. In a case where the nozzle 22 is inserted toward theultrasonic vibrating part 400 from the upper part of FIG. 5 and thecleaning is performed, cleaning unevenness occurs in the region (403 or404) in which the cavitation occurs and in the region in which thecavitation does not occur. In addition, the ultrasonic intensity in theregion 403 close to the ultrasonic vibrating part 400, is strong andappropriate for the cleaning.

In the embodiment, as described above, by disposing the vibrating part323 of the diaphragm 202 which is the ultrasonic vibrating part 400 onthe side surface in the cleaning tank, the tip end of the nozzle 22 canbe inserted into the region having high ultrasonic intensity. Therefore,it is possible to effectively clean a wide area of the side surface ofthe tip end of the nozzle 22.

FIG. 6 is a view illustrating a relationship between the cleaning liquidand the nozzle position in the ultrasonic cleaner of the embodiment.FIG. 6(a) is a schematic view of a cleaning range, and FIG. 6(b) is aview illustrating a positional relationship between the nozzle 22, andthe cleaning liquid and the center of diaphragm on the section of thecleaner, respectively. Since the cleaning range is limited when thenozzle 22 dispenses the sample, the liquid surface of the sample isdetected so that the sample is inserted only to the limited position ofthe tip end of the nozzle 22, and the position at which the nozzle 22 islowered is controlled. Since the method of detecting the liquid surfaceof the sample and a lowering controlling method in the nozzle 22 areknown methods, the detailed description thereof will be omitted. Sincethe nozzle 22 is inserted into the sample to the limited depth asdescribed above, a range 501 to which the sample adheres aftersuctioning the sample is limited to a certain range. Therefore, if arange 502 in which the cleaning is performed by the ultrasonic cleaner26 is a range wider than the sample-attached range 501, an unwashed partis unlikely to be generated. In a case where the cleaning liquid is usedby the ultrasonic cleaner 26, further, it is necessary to perform thewashing with water and not to make the water brought into the sample,and it is necessary that a range 503 in which the cleaning is performedby the water is wider than a range in which the cleaning is performed bythe ultrasonic cleaner 26. However, when the range 503 of the watercleaning is wide, the time which is taken for the water cleaningincreases. Therefore, it is desirable that the range 503 of the watercleaning and the cleaning range 502 are set to be narrow as much aspossible.

In the ultrasonic cleaner 26, the cleaning liquid is stored in thecleaning tank 211. The cleaning liquid may be the water, but it ispreferable to use the cleaning liquid which can remove the contaminantsby a chemical action. The cleaning liquid has the liquid surface on apool 512 of the cleaning tank from a bottom 511 of the cleaning tank,and the height from the bottom 511 of the cleaning tank to the pool 512of the cleaning tank becomes a liquid level 513. When the nozzle 22 isinserted into the cleaning tank 211, the range from a nozzle tip endposition 514 to a cleaning tank pool 512 which is the liquid surface isthe nozzle cleaning range 502 of the ultrasonic cleaner 26.

The diaphragm 202 of the ultrasonic cleaner 26 of the embodiment has aconfiguration in which the deformation amount is enlarged at the centerpart of the diaphragm as described above, and the ultrasonic intensityin the cleaning liquid also increases in the vicinity of the center ofthe diaphragm. In order to effectively clean the nozzle 22, it ispreferable that the nozzle passes through a center line 515 of thediaphragm, and to stop the nozzle so that the center line 515 isincluded in the nozzle cleaning range 502. In other words, it ispreferable that the cleaning range 502 is narrow in the ultrasoniccleaner 26 in which the cleaning liquid is used is narrow, and thenozzle tip end is inserted to be equal to or lower than the center line515 of the diaphragm having a high cleaning effect. In other words, itis desirable that the nozzle tip end position 514 is below the centerline 515. Therefore, regarding the liquid level 513 of the cleaningliquid, it is preferable that the liquid level of the cleaning liquidsatisfies the following expression when a length 516 from the fixing endof the diaphragm 202 to the fixing end is defined as D, the cleaningrange 502 of the nozzle is defined as h, and the liquid level 513 isdefined as H. In other words, it is desirable to perform the cleaning bystopping the nozzle to satisfy the expression 1. In other words, it isdesirable that the liquid level of the liquid in the cleaning tank islower than the position at which the length of the cleaning range of thedispensing nozzle is added to the height of the center line of thediaphragm, and the tip end of the dispensing nozzle when inserting thedispensing nozzle into the cleaning tank is inserted to be equal to orlower than the center line of the diaphragm and the cleaning isperformed.(Expression 1)D/2≤H≤D/2+h  (Expression 1)

FIG. 7 is an example of a pipe configuration in the ultrasonic cleanerof the embodiment. In order to supply the cleaning liquid or the waterto the ultrasonic cleaner 26, a pipe 601 is connected to a lower part ofthe cleaning tank 211. A syringe pump 602 for extruding the liquid bypressure, a cleaning liquid tank 603 in which the cleaning liquid isstored, a pipe 604 which is connected to water works facilities andsupplies the water, and a switching valve 605 for switching theconnection of the pipe, are connected to the pipe 601. Furthermore, areceiver (overflow receiver 606) for receiving the cleaning liquidoverflowed to the pool 512 of the cleaning port 203, and a pipe (notillustrated) which is connected to a sewage system, are provided. Inother words, a receiver for making the liquid in the cleaning tankoverflowed is provided at the upper part of the cleaning tank.

In the cleaning tank 211, the water or the cleaning liquid is alwaysstored, new liquid is supplied by the pressure of the syringe pump 602,the overflowed liquid is discharged to the receiver 606, and then, thedischarged liquid flows to sewage. The syringe pump 602 and theswitching valve 605 can be operated by a command from the CPU board (notillustrated) which controls the device, can supply the cleaning liquidwhen performing the ultrasonic cleaning of the nozzle 22, can supply thewater when the cleaning is not performed for a long period of time andstore the water. Regarding the cleaning liquid in the cleaning tank 211,it is preferable that the entire cleaning liquid after the cleaning isreplaced for reducing the carry-over. In the configuration of theembodiment, by operating the syringe pump 602, it is possible to supplynew cleaning liquid to the cleaning tank 211, to discharge the cleaningliquid used in the cleaning to sewage by the overflow, and to replacethe cleaning liquid in the cleaning tank 211. In addition, it isdesirable to supply the liquid for performing the cleaning to thecleaning tank only when the ultrasonic cleaning is used, and to supplyand store the water in the cleaning tank when the ultrasonic cleaning isnot used. This is because it is possible to suppress useless consumptionof the liquid (cleaning liquid) for performing the cleaning.

FIG. 8 is an example of a processing flow of the nozzle cleaning inwhich the ultrasonic cleaner of the present invention is used. At thetime of S701 when the device is in an operation state, the sampledispensing mechanism 15 repeats S711 of sampling processing. In S711 ofthe sampling processing, S712 of dispensing (suctioning of the sampleand ejecting of the sample) is performed, and after this, the cleaningprocessing is performed, but, S713 of determining whether or not asample to be dispensed next is the same sample, is performed. As aresult, if the sample to be handled next is the same sample, only S714of the water cleaning is performed by the cleaning tank 27, and in acase where a different sample is handled, the sample which adheres tothe nozzle is cleaned by S715 of the ultrasonic cleaning (for normalprocessing) by the ultrasonic cleaner 26, and after this, the washing isperformed by the cleaning liquid by S716 of the water cleaning by thecleaning tank 27. In this manner, in the middle of the operation, it isdesirable that it is determined whether or not the sample to be handlednext is the same sample, only the water cleaning is performed when thesample to be handled next is the same sample, and the cleaning in whichthe ultrasonic cleaner is used and the water cleaning are performed whenthe sample to be handled next is a different sample.

In the description above, according to the result of S713 of the sampledetermination processing, a case of only S714 of water cleaningprocessing and a case of S715 of the ultrasonic cleaning and S716 of thewater cleaning are divided, but S715 of the ultrasonic cleaningprocessing may be used every time when the sampling is performed.However, in this case, an amount of the cleaning liquid used increasesand the cleaning cost increases.

When the device is in S702 of a maintenance state, it is possible toperform S721 of maintenance processing of cleaning a small amount ofcontaminants accumulated in the nozzle 22. In S701 of the operationstate, in order to prevent a throughput of the sampling processing frombeing dropped, it is necessary that the cleaning is performed during ashort period of time, but in S702 of the maintenance state, the nozzle22 can be cleaned taking time. In S722 of the ultrasonic cleaning (formaintenance) in S721 of the maintenance processing, it is possible toperform the cleaning (that is, deep insertion into the cleaning tank211) by widening the nozzle cleaning range 502. In S722 of theultrasonic cleaning (for maintenance), the cleaning is performed over alonger period of time than the ultrasonic cleaning (for normalprocessing). After this, in S723 of the water cleaning processing, arange wider than a normal range is washed with the water.

It is preferable to periodically perform S721 of the maintenanceprocessing, and for example, it is possible to prevent the contaminantsfrom being accumulated to the nozzle 22 by performing the S721 one timea day.

In this manner, in the operation state and in the maintenance state, byhaving parameters in which the cleaning time of the ultrasonic cleaneror the insertion depth of the dispensing nozzle vary, the automaticanalyzer can perform the control as described above.

In addition, in the cleaning flow of the present invention, an operationof dropping a water droplet by vacuum suction or the like after thewater cleaning, may be added.

FIG. 9 is an appearance view of an example in which a shape of thecleaning tank of the ultrasonic cleaner of the present invention ischanged. FIG. 9(a) illustrates a cleaning port, and FIG. 9(b) is asectional view of the ultrasonic cleaner, respectively. An ultrasoniccleaner 900 is not different from the ultrasonic cleaner 26 in themethod of use or the installation position, except that a cleaning tank902 part of a cleaning port 901 has a conical shape unlike theultrasonic cleaner 26.

By changing the part in which the liquid of the cleaning tank 902 isstored to a conical shape, it is possible to reduce an amount of thecleaning liquid to be used, and further, the ultrasonic wave generatedfrom the diaphragm 202 can be reflected by a surface 903 on the cleaningtank side of the cleaning port 901, it is possible to concentrate theoccurrence of the cavitation on the periphery of the nozzle 22 insertedinto the cleaning tank 902, and thus, it is possible to effectivelyperform the cleaning.

According to the ultrasonic cleaner having the above-describedconfiguration, it is possible to effectively generate the cavitation inthe cleaning range of the nozzle 22 in which the sample is dispensed,and to effectively clean the nozzle.

Example 2

FIG. 10 is an appearance view of an example of the ultrasonic cleaner ofthe embodiment. The embodiment is an example in which a vibrating part222 is used instead of the diaphragm used above. FIG. 10(a) is aperspective view of the ultrasonic cleaner, FIG. 10(b) is an upper viewof the ultrasonic cleaner, and FIG. 10(c) is a sectional view of theultrasonic cleaner, respectively. The sectional view (c) is a sectionalview of a location illustrated by a dashed line of a locationillustrated by A. The ultrasonic vibrating means of the ultrasoniccleaner 200 (26) of the present invention is the BLT 100.

The ultrasonic cleaner 200 fixes a plate spring 221 and the vibratingpart 222 to the BLT 100 by a bolt 224, and both ends of the plate spring221 are fixed to a cleaner base 223.

In the cleaner base 223, the cleaning tank 211 which can store thecleaning liquid and a liquid feeding port 225 which connects a tube thatfeeds the cleaning liquid to the cleaning tank 211 are provided, thecleaning liquid is overflowed to a groove on the periphery by feedingthe cleaning liquid to the cleaning tank 205, and the cleaning liquidcan be replaced. In addition, the overflowed cleaning liquid on theperiphery of the cleaning tank 205 enters a hole 226 for the discharge,and the cleaning liquid is discharged through a discharge port 208connected to the discharge pipe. The nozzle 22 can be inserted into thecleaning tank 211 in which the cleaning liquid is stored, from the upperpart of the cleaning tank 211.

The ultrasonic cleaner 200 transmits the vibration of the BLT 100 to thevibrating part 222, and further, the tip end (the lowest end) of thevibrating part 222 extends to the inside of the cleaning tank 205, andthe vibration can be transmitted to the cleaning liquid in the cleaningtank 211. In other words, the vibrating part 222 in the cleaning liquidcan generate the ultrasonic wave from the side surface of the nozzle 22due to the driving of the BLT 100. In other words, the vibrating part222 has a shape which extends along the dispensing nozzle, and has afirst part at which the vibrating part 222 is inserted into the cleaningtank, and the ultrasonic vibrator can vibrate the first part in thehorizontal direction via a second part above the first part. Inaddition, the ultrasonic cleaner 200 can replace the cleaning liquid bythe overflow after performing the cleaning of the nozzle 22.

In order to effectively clean the tip end of the nozzle 22, it isdesirable that the vibrating part 222 is disposed to be parallel to thenozzle 22, or it is desirable that the nozzle is inserted at a positionclose to the vibrating part 222. Unlike the example of the diaphragm, itis possible to insert the nozzle at a position close to the vibratingpart 222 without providing the opening part 210 a part of whichprotrudes. In addition, unlike the example of the diaphragm, it ispossible to obtain a high cleaning effect without providing the sealingmaterial for preventing the diaphragm or the liquid leakage on the sidesurface of the cleaning tank 211. It is desirable that the plate spring221 has a shape in which the vibrating part 222 is not twisted so as togenerate a parallel displacement, and the plate thickness is thin inorder to increase the displacement of the vibrating part 222.

In the vibrating part 222, in addition to the plate-like vibrating partas described in FIG. 10(c), a rod-like vibrating part having a certaindegree of thickness is also included. The shape of the vibrating part222 is not particularly limited as long as the vibrating part 222 is amember which can be inserted into the cleaning tank 211 and vibrates inthe horizontal direction. In addition, the vibrating part 222 may not beconfigured of a single member, but of a plurality of members.

In addition, FIGS. 6 and 9 can also be similarly employed in the exampleof the vibrating part 222.

Example 3

Next, another structure of the ultrasonic cleaner 26 will be described.The ultrasonic cleaner 26 generates the ultrasonic wave in the cleaningtank. As will be described later, the ultrasonic cleaner 26 is providedwith the vibrating part which is inserted into the cleaning liquid inthe cleaning tank, and transmits the ultrasonic vibration to thecleaning liquid, and the ultrasonic vibrator which is configured byfixing and fastening the piezoelectric element with two or more metalblocks by the bolt, and generates the ultrasonic vibration to thevibrating part. The vibrating part is mainly different from that ofExample 2 in that a hollow part 1209 is provided.

FIG. 11 is an appearance view of an example of the ultrasonic cleaner.FIG. 11(a) is an upper view, FIG. 11(b) is a front view, FIG. 11(c) is asectional view (section taken along A-A of the upper view (a)), and FIG.11(d) is a perspective view of the ultrasonic cleaner, respectively. Anultrasonic cleaner 1200 includes an ultrasonic vibrator 1201, avibrating part 1202, and a plate spring 1203. The ultrasonic cleaner1200 is configured to interpose the plate spring 1203 between theultrasonic vibrator 1201 and the vibrating part 1202, and to be fixed bya bolt 1204. Furthermore, two columns of a cleaner base (made of metal)1205 which is a part of the automatic analyzer protrudes upward, andboth end parts of the plate spring 1203 are fixed to the two columns ofthe cleaner base 1205. A tip end of the vibrating part 1202 ispositioned in a cleaning tank 1206 which is on the cleaner base 1205,and in particular, the vibrating part 1202 is in contact with thecleaning tank 1206, and the tip end thereof is a free end. In otherwords, the vibrating part 1202 is fixed to the side surface of a metalblock 1211 which will be described later and an upper part of thecleaning tank 1206, and the tip end of the vibrating part 1202 which isinserted into the cleaning liquid in the cleaning tank vibrates as afree end according to the vibration in the horizontal direction of theside surface.

The tip end of the vibrating part 1202 is provided with a cylindricalhole, and the hole passes through to a bottom of the vibrating part 1202(refer to FIGS. 11(a) and 11(c)). Therefore, the vibrating part 202includes the hollow part 1209, the nozzle 22 can be inserted into thehollow part 1209, and the hollow part 1209 is filled with the cleaningliquid.

In addition, it is possible to supply the cleaning liquid or the waterfrom a supply port 1207 to the cleaning tank 1206, to make the liquidwhich enters the cleaning tank 1206 overflowed by supplying the liquidhaving an amount which is equal to or greater than a certain amount, andto discharge (replace the liquid by the overflow) the liquid to theoutside of the ultrasonic cleaner 1200 from a discharge port 1208. Inaddition, the tip end of the vibrating part 1202 after supplying thecleaning liquid can also be immersed in the cleaning liquid stored inthe cleaning tank 1206.

When cleaning the nozzle 22 by the ultrasonic cleaner 1200, by insertingthe nozzle 22 into the hollow part 1209 which is at the tip end of thevibrating part 1202, the tip end part (range of being in contact withthe sample) of the nozzle 22 is immersed in the cleaning liquid. Byinputting sine wave voltage which is, for example, equal to or greaterthan 20 kHz to the ultrasonic vibrator 1201, the ultrasonic vibrator1202 performs the ultrasonic vibration in the arrow direction.Accordingly, the tip end part of the vibrating part 1202 also performsthe ultrasonic vibration, the cavitation occurs in the cleaning liquidof the hollow part 1209, and the nozzle 22 can be strongly cleaned.

In particular, in the configuration of the ultrasonic cleaner 1200,since it is possible to generate the cavitation from the differentdirection with respect to the side surface of the nozzle 22, it ispossible to perform the cleaning without unevenness with respect to therange in which the tip end is cleaned. In addition, since the tip end ofthe vibrating part 1202 is a free end, at the tip end of the vibratingpart 1202, the amplitude of the ultrasonic vibrator 1201 can beamplified, and many cavitations can occur. Additionally, since thedistance between a vibration surface (inner circumference of a cap,here, a cylinder is referred to as a cap for convenience) which performsthe ultrasonic vibration and the nozzle 22 is shortened, it is possibleto generate the cavitation having high density with respect to the rangein which the tip end of the nozzle 22 is desired to be cleaned.According to the two actions, it is possible to realize a strongcleaning effect. In addition, the cleaning force can be appropriatelyadjusted by adjusting the length in the perpendicular direction of thevibrating part 1202 and by adjusting the diameter of the hollow part1209. For example, regarding the former adjustment, it is possible toincrease the amplitude of the vibration surface by increasing thelength, and regarding the latter adjustment, it is possible to shortenthe distance between the vibration surface and the nozzle 22 bydecreasing the diameter.

Since the contaminants which adhere to the nozzle 22 by cleaning thenozzle 22 are mixed into the cleaning liquid in the cleaning tank 1206,it is desirable to replace the cleaning liquid after cleaning the nozzle22. However, if the cleaning liquid is replaced every time the nozzle 22is cleaned, since a large amount of the cleaning liquid stocked in thedevice is necessary, it is desirable to reduce the amount of thecleaning liquid which is necessary for cleaning the nozzle 22. In theultrasonic cleaner 1200, it is possible to replace the cleaning liquidby making the cleaning liquid overflowed, and to clean the nozzle 22when the cleaning liquid is overflowed in the cap of the tip end of thevibrating part 1202. In other words, it is possible to make the shape ofthe cleaning tank 1206 small within a range in which the outer side ofthe vibrating part 1202 is not in contact, and to reduce the amount ofthe cleaning liquid to be used by reducing the size of the cleaning tank1206.

The ultrasonic vibrator 1201 of the ultrasonic cleaner 1200 considersthe BLT, and the BLT generally has a structure of interposing a piezoelement (hereinafter, referred to as a piezoelectric element) 1213 bytwo metal blocks (1211 and 1212), and fastening and fixing by the bolt(not illustrated) on the inside. In the BLT, since the piezoelectricelement is interposed by the metal blocks having a relatively largeweight, and fastened and fixed by the bolt, it is possible to lower thevibration frequency of the piezoelectric element on the metal blockside. The frequency band of the piezoelectric element of the embodimentis a band for an element which oscillates in a frequency band in whichthe cavitation is relatively unlikely to occur. However, it is possibleto configure the ultrasonic cleaner which vibrates in a frequency band(20 kHz to 100 kHz) in which the cavitation is likely to occur, of theBLT.

The ultrasonic cleaner 1200 is fixed by the cleaner base 1205 via theplate spring 1203 at a part at which the vibration amplitude of theultrasonic vibrator 1201 increases (an antinode of the vibration). Whenthe plate spring 1203 has a shape having high rigidity, the amplitude ofthe vibrating part 1202 is not sufficiently obtained, and the cleaningeffect of the nozzle 22 deteriorates. Therefore, a shape in which theplate thickness of the plate spring 1203 is thin and the width isnarrow, is desirable.

As the distance between the ultrasonic vibrator 1201 and the vibratingpart 1202 is shortened, the size of the cleaner can be reduced, andthus, it is also possible to mount the ultrasonic cleaner 1200 on theautomatic analyzer having a limited installation space.

In the embodiment, a structure in which the cylindrical hole is providedas the hollow part at the tip end of the vibrating part 1202 isdescribed. However, the invention is not necessarily limited to theconfiguration as long as a high cleaning effect is obtained and aneffect in which the cleaning unevenness does not occur is considered.For example, the hole may be an elliptical or polygonal columnar hole.Otherwise, the hole may be a hole having an uneven width in the depthdirection not to have a shape of a column, but to have a shape of a partof a cone or a part of a polygonal cone. In this manner, the vibratingpart 1202 may have a shape a part of which is chipped, in addition tothe shape which covers the entire circumferential direction of thenozzle 22.

In a case of the shape a part of which is chipped, it is desirable thata position at which a part is chipped is a position which does notintersect a straight line when drawing the straight line in thevibrating direction of the vibrating part 1202 from the position of thenozzle 22 on a horizontal section.

For example, in a case of the shape a part of which is chipped by usingthe shape which covers the entire circumferential direction of thenozzle 22 as a reference, it is desirable to provide the position atwhich a part is chipped at an intersecting position when drawing thestraight line in the direction perpendicular to the vibrating directionof the vibrating part 1202 from the position of the nozzle 22.

For example, a shape which interposes the nozzle 22 by parallel flatplates or the like may be employed as the shape a part of which ischipped. In this case, the disposition of the position at which a partis chipped is also similar. In other words, it is desirable to employflat plates which oppose each other in the vibrating direction of thevibrating part 1202.

Here, the reason of occurrence of the cleaning unevenness will bedescribed. In a case where the ultrasonic wave is generated from theside surface in one direction of the nozzle 22, on the side opposite tothe nozzle 22, a shade region in which the ultrasonic wave is unlikelyto sneak is generated, and unevenness occurs in the occurrence amount ofthe cavitation in the front surface direction and in the rear surfacedirection of the nozzle 22. Therefore, by generating the ultrasonic wavefrom the plural directions with respect to the nozzle 22 from thevibrating part 1202, it is possible to eliminate the shade region.Accordingly, it is possible to suppress the cleaning unevenness byconfiguring the vibrating part so that the part which vibrates insynchronization with the vibration of the vibrating part 1202 isdisposed in the plural directions when viewed from the nozzle 22.Therefore, in the embodiment, it is also possible to further suppressthe cleaning unevenness by the vibrating part of Example 2.

However, since the surface perpendicular to the vibrating direction is asurface which contributes to generating cavitation the most, it ispossible to most efficiently obtain a high cleaning force by achieving ashape of the vibrating part 1202 in which a part is disposed at twopositions which intersect each other when drawing a straight line in thevibrating direction of the vibrating part 1202 by using the position ofthe nozzle 22 as a starting point on the horizontal section.

Here, the hollow part 1209 will be described. As described above, thevibrating part 1202 may have various shapes, and a shape in which thepart is disposed in the plural directions when viewed from the nozzle 22may be employed. Therefore, the hollow part 1209 does not necessarilymean only the inner side of a shape which covers the entirecircumferential direction of the nozzle 22. In addition, regardless ofthe continuity of the part, in the specification, the inner sidesurrounded by the plural parts corresponds to the hollow part 1209.

As described above, it is more desirable that the parts are thevibrating part 1202 provided with an opposing part via the hollow part1209 considering the efficiency rather than that the parts which aresimply disposed in the plural directions. In other words, it isdesirable that the vibrating part 1202 is provided with two surfacesopposing each other via the hollow part 1209. This is because the shaderegion generated on one surface can be eliminated by the other surface.Here, opposing surfaces means not only the parallel surfaces, but alsothat an inclination between the surfaces to a certain degree is allowed.For example, the inclination angle between the surfaces may be 30°, andis considered to be opposing when the inclination angle is less than90°.

However, it is desirable that the two surfaces oppose each other in thevibrating direction of the vibrating part. In other words, two surfaceswhich interpose the hollow part 1209 and are perpendicular to thevibrating direction are desirable. In addition, not only the plane butalso a curved surface described in the embodiment is also included inthe perpendicular surface. In the embodiment, the vibrating part 1202has a shape which surrounds the entire periphery of the hollow part1209, and the two surfaces are inner wall surface having the shape.

Next, the effects will be described. As described above, by using theultrasonic cleaner provided with the ultrasonic vibrator of the BLT andthe vibrating part having the hollow part, it is possible to provide theautomatic analyzer or the like which can obtain a high cleaning effectwithout the cleaning unevenness with respect to the dispensing nozzle bycleaning the dispensing nozzle by generating the ultrasonic vibration inthe vibrating part in a state where the dispensing nozzle is insertedinto the hollow part.

In addition, since the ultrasonic cleaner of a type of inserting thevibrating part into the cleaning tank is employed, it is possible togenerate the ultrasonic wave at the amplitude which is greater than theamplitude of the ultrasonic vibrator. In addition, it is possible tomake the vibrating part approach the dispensing nozzle, and to clean thedispensing nozzle by higher cleaning force.

In addition, as the vibrating part is provided with two surfacesopposing each other via the hollow part, it is possible to moreeffectively eliminate the cleaning unevenness than the case where twosurfaces do not oppose each other.

In addition, as the two surfaces are surfaces opposing each other in thevibrating direction of the vibrating part, it is possible to much moreeffectively eliminate the cleaning unevenness. Additionally, in a caseof this shape, each surface vibrates in the opposite phase around thenozzle. The cleaning liquid interposed therebetween largely waves by thevibration of the opposite phase. The cleaning liquid contaminated by thenozzle cleaning climbs over the surface and moves to the outside of thehollow part by the waving action. Accordingly, the cleaning liquid whichis not contaminated flows into the hollow part from the lower side ofthe hollow part. Therefore, it is possible to suppress re-adhesion of acontamination source to the nozzle by the action of the flow of thecleaning liquid.

In addition, as the vibrating part has a shape which surrounds theentire periphery of the hollow part and two surfaces are inner wallsurfaces having the shape, it is possible to manufacture the vibratingpart by a simple processing method of opening a hole in the vibratingpart. Therefore, it is possible to manufacture a high-performancevibrating part at comparatively low cost. In addition, as describedabove, similar effects can also be obtained in a case of a polygonalcolumnar shape, but from the viewpoint of the processing cost, thecylindrical columnar shape is the most appropriate.

In addition, in a configuration in which a plurality of ultrasonicarrays are disposed on the inner side of the cleaning tank as describedin PTL 2, a difficulty of attaching each element of the ultrasonic arrayis considered, and the control of the plurality of ultrasonic arraysbecomes complicated. Meanwhile, in the embodiment, a simpleconfiguration is achieved since the configuration of inserting thevibrating part is employed, and the driving control is easily performedsince the number of ultrasonic generating sources is practically one.

In addition, when the configuration of PTL 2 is employed, even in a casewhere a part of the ultrasonic array is damaged, since other ultrasonicarrays are driven, it is difficult to notice the abnormality, and a casewhere the fact that the expected cleaning effect is not obtained is notnoticed can be considered. Meanwhile, in the embodiment, in a case wherethe ultrasonic vibrator is damaged, since the cavitation is notgenerated at all, it is possible to easily notice the abnormality.

In addition, when the plurality of ultrasonic arrays are disposed on theinner side of the cleaning tank as described in PTL 2, while complicatedunevenness is generated on the inner side of the cleaning tank, in theembodiment, the inner side of the cleaning tank has a shape of a curvedsurface which does not have the unevenness. Therefore, in a case ofperforming the maintenance to wipe out the inside of the cleaning tank,the maintenance becomes easy. In addition, in the embodiment, since aconfiguration of removing the vibrating part from the ultrasonicvibrator is employed, it is also possible to easily perform themaintenance or replacement by wiping-out of the vibrating part.

Example 4

In Example 3, a configuration in which a high cleaning effect withoutthe cleaning unevenness is obtained is mainly described. However, whenrepeatedly performing the cleaning by the ultrasonic wave, theultrasonic vibrator 1201 generates heat (depending on the drivingcondition, but there is a case where the temperature is equal to orgreater than 50 degrees), and the heat moves to the vibrating part 1202.In particular, in a case where the distance between the ultrasonicvibrator 201 and the vibrating part 1202 is short similar to thevibrating part 1202 similar to the ultrasonic cleaner 1200, thetemperature of the vibrating part 1202 becomes high temperature to thedegree which is the same as that of the ultrasonic vibrator 1201. Thecleaning liquid is supplied to the periphery of the tip end of thevibrating part 1202, but the heat of the vibrating part 202 moves duringa short period of time since the amount thereof is small, and further,the nozzle 22 inserted into the cleaning tank 1206 for performing thecleaning is warmed. The water temperature in the automatic analyzer isgenerally normal temperature (approximately 25 degrees), and an increasein a difference between the temperature of the nozzle 22 and the normaltemperature influences the dispensing performance. Since both a largedifference and a small difference between the temperature of the nozzleand the water temperature influence the dispensing performance, it isdesirable that the difference between the temperature of the nozzle 22and the normal temperature is small. In order to reduce the influence,it is desirable to radiate the heat before the heat from the ultrasonicvibrator 1201 moves to the vibrating part.

Since the metal plate spring 1203 is also disposed between theultrasonic vibrator 1201 and the vibrating part 1202 in the example ofFIG. 11, it cannot be said that the heat radiation effect is notobtained at all, but as described above, since a thin plate is employed,the heat radiation effect is relatively small. Therefore, in thefollowing embodiment, a configuration for increasing the heat radiationeffect will be described. In addition, since the shape of the tip end ofthe vibrating part 1202 is similar to that of the Example 3, thedescription of the configuration and the effect will be omitted.

FIG. 12 is an appearance view of an example of the ultrasonic cleaner(only the vibration part) having a structure in which a heat radiationeffect higher than that of Example 3 is obtained. FIG. 12(a) is an upperview, FIG. 12(b) is a side view, FIG. 12(c) is a perspective view of theultrasonic cleaner, and FIGS. 12(d) and 12(e) are schematic views of thecleaning part, respectively. However, the cleaning tank in which thecleaning liquid is stored is similar to FIG. 11, and is omitted in FIG.12. Similar to the ultrasonic cleaner 1200, an ultrasonic cleaner 1300uses a BLT type ultrasonic vibrator 1301, but instead of the platespring 1203, a piezo element 1313 and a metal member 1314 are interposedbetween metal blocks 1311 and 1312, and are fastened and fixed by thebolt (not illustrated) in the ultrasonic vibrator 1301. The metal member1314 can be fixed to an ultrasonic vibrator base 1302, and a vibratingpart 1303 is fixed to the ultrasonic vibrator 1301 by the bolt or thelike. A tip end of the vibrating part 1303 is the same as that of theultrasonic cleaner 1200, and is immersed in the cleaning liquid in thecleaning tank 1206 (not illustrated in FIG. 12). In a state where thenozzle 22 is inserted into the cleaning tank 1206 and approaches thevibrating part 1303, by driving the ultrasonic vibrator 1301, the tipend of the nozzle 22 can be cleaned.

The ultrasonic cleaner 1300 is fixed to the ultrasonic vibrator base(made of metal) 1302 via the metal member 1314 at a part at which thevibration amplitude of the ultrasonic vibrator 1301 does not becomelarge (a node of the vibration). Unlike the ultrasonic cleaner 1200, theplate spring 1203 is not necessary and without making the platethickness of the metal member 1314 thin similar to the plate spring1203, the amplitude of the vibrating part 1202 can be sufficientlygenerated. The metal member 1314 is adjacent to the piezo element 1313which is a heat generation source, and the heat when driving theultrasonic vibrator 1301 moves to the metal member 1314 from the piezoelement. After this, the heat moves in order of the metal block 1311 andthe vibrating part 1303, and when the vibrating part 1303 is heated, thenozzle 22 is warmed via the cleaning liquid when cleaning the nozzle 22.However, a heat capacity increases since the plate thickness in themetal member 1314 can be thick (the volume increases) compared to theplate spring 1203, and the movement of the heat to the vibrating part1303 can decrease compared to the ultrasonic cleaner 1200. Therefore, byproviding the metal member 1314 and the ultrasonic vibrator base (madeof metal) 1302, it is possible to effectively radiate the heat, and tosuppress the movement of the heat to the vibrating part 1303.

In particular, in order to improve the heat radiation properties, it isdesirable that the material of the metal member 1314 and the ultrasonicvibrator base 1302 is a material having higher thermal conductivity thanthat of the metal block 1311 or the vibrating part 1303, and byradiating the heat from the metal member 1314 or by integrally movingthe heat to the ultrasonic vibrator base 1302, the heat from the piezoelement 1313 is unlikely to be moved to the vibrating part 1303.

Furthermore, as means for increasing the heat radiation efficiency fromthe metal member 1314, there is a method of providing a fin structure inthe metal member 1314 or the ultrasonic vibrator base 1302, increasingthe surface area, and sticking a heat sink to the metal member 1314. Inaddition, in the structure of the ultrasonic cleaner 1300, it ispossible to cool the metal member 1314 by cooling the ultrasonicvibrator base 1302, and to suppress the movement of the heat to thevibrating part 1303. As cooling means, there are a method of attaching afan for air cooling or a water cooling tube to the ultrasonic vibratorbase 1302, and a method of attaching a Peltier element.

As described above, similar to the ultrasonic cleaner 1200, thevibrating part 1303 is used by disposing the tip end part in thecleaning tank 1206, but when the shape of the tip end part has a shapeof a plane, and when the shape is a shape of a curved surface, it ispossible to clean the nozzle 22. However, as described above, byproviding a hollow part 1320 to surround the nozzle 22 in the tip endpart of the vibrating part 1303 in a shape of a cup, it is possible toeffectively clean the entire circumference of the nozzle 22.Furthermore, even in a case of a shape of a cup, by making the hollowpart 1320 as a through hole, it is also possible to replace the cleaningliquid in the hollow part 1320, similar to the ultrasonic cleaner 1200,the ultrasonic cleaner 1300 can correspond to the overflow structure ofthe liquid. In particular, by making the shape of a cup, since it ispossible largely increase the surface area of the surface which is incontact with the liquid of the vibrating part 1303, it is possible toincrease a cooling effect by the overflow of the liquid which will bedescribed later.

FIG. 13 is an appearance view of an example of the ultrasonic cleanerhaving the heat radiation structure (cooling structure) of theembodiment. FIG. 13(a) is an upper view, FIG. 13(b) is a rear view, FIG.13(c) is a sectional view, and FIG. 13(d) is a perspective view (sectiontaken along A-A of the rear view (b)) of the ultrasonic cleaner,respectively. An ultrasonic cleaner 1400 has a structure similar to thatof the ultrasonic cleaner 1200, and is different from the ultrasoniccleaner 1200 in that a tube 1402 for radiating the heat (cooling) isprovided in an ultrasonic vibrator 1401. As described above, the BLTinterposes the piezo element by the two metal blocks, and is fastened bythe internal bolt, and in the ultrasonic cleaner 1400, a hole is open inan internal bolt 1403 and two tubes 1402 pass through the hole. In FIG.13, the tube 1402 enters from the side surface of the ultrasonicvibrator 1401, is removed from the rear surface, and enters theultrasonic vibrator 1401 from the rear surface, and finally, goes out ofthe side surface of the ultrasonic vibrator 1401. In addition, astructure in which the inside of the tube 1402 is filled with the fluid(for example, water) and the circulation is possible by a pump (notillustrated), is employed. At a part of the tube 1402 which is on theoutside of the ultrasonic cleaner 1400, the fluid in the tube 1402 canradiate (cool) the heat of the piezo element through the cooling means,such as a cooler. As the cooling means, a cooling function of a coldinsulation box (a part of the reagent disk 12) for insulating thereagent which is in the automatic analyzer 10, may be used. According tothe above-described configuration, the generated heat of the piezoelement 1213 can be radiated to the outside of the ultrasonic cleaner1400 by the circulation of the fluid which passes through the inside ofthe tube 1402, and the movement of the heat to the vibrating part 1202can be suppressed.

In FIG. 13, a configuration in which the disposition of the tube 1402enters from the side surface of the ultrasonic vibrator 1401 and goesout of the rear surface is illustrated, but the heat radiation (cooling)is possible even when the surface or the position at which the tube 1402enters and goes out is different from that of FIG. 13. In addition, theflow path may be directly formed in the ultrasonic vibrator 1401 withoutusing the tube 1402, or the tube may be connected to the flow path. Itis preferable that the tube 1402 is made of a material which isresistant to high temperature of the piezo element 1213 and has lowrigidity which does not influence the vibration of the ultrasonicvibrator 1401.

Similar to the ultrasonic cleaner 1200, since the ultrasonic cleaner1400 also has the overflow structure of the liquid, it is possible toradiate the heat (cool) by the overflow of the liquid which will bedescribed late.

In addition, as a method in which the cooler is not used as the coolingmeans, there is also a method in which the above-described heat sink,the cooling fan, or the Peltier element is used.

FIG. 14 is an example of the liquid overflow structure and the pipeconnection in the ultrasonic cleaner of the embodiment. In order tosupply the cleaning liquid or the water to the ultrasonic cleaner 26, apipe 1501 is connected to a lower part of the cleaning tank 1206. Asyringe pump 1502 for extruding the liquid by pressure, a cleaningliquid tank 1503 in which the cleaning liquid is stored, a pipe 1504which is connected to water works and supplies the water to the waterworks facilities, and a switching valve 1505 for switching theconnection of the pipe, are connected to the pipe 1501. Furthermore, apipe 1506 which is connected to the sewage and discharges the liquid toa sewage system after the liquid overflowed from the cleaning tank 1206passes through the discharge port 1208, is provided. In theabove-described configuration, by controlling the syringe pump 1502 andthe switching valve 1505, it is possible to supply the cleaning liquidor the water to the cleaning tank 1206. In addition, as illustrated in aflow path 1507 of the liquid at the time of the overflow, the liquidwhich is in the cleaning tank 1206 is overflowed by supplying theliquid, and the liquid can be discharged to the sewage by the overflow.The syringe pump 1502 or the switching valve 1505 operate by the commandfrom the control portion 28 which controls the device, and can controlthe number of overflows or the type (water or cleaning liquid) of theliquid.

The overflow of the liquid described above can be used in radiating theheat from the tip end part of the vibrating part (1202 or 1303) in acase where the heat from the ultrasonic vibrator (any of 1201 to 1401)moves to the tip end part of the vibrating part (1202 or 1303). Inparticular, by repeating the overflow of the liquid plural times, theheat radiation to the liquid from the vibrating part, the discharge ofthe heated liquid, and the supply of the liquid having a normaltemperature, are repeated (since the water works have a normaltemperature, the temperature is lower than that of the heated vibratingpart). Therefore, by repeating the overflow plural times, it is possibleto discharge the heat from the tip end part of the vibrating part (1202or 1303). In addition, instead of repeating the overflow plural times,the liquid may be continuously overflowed for a long period of time. Inaddition, in order to suppress the amount of the cleaning liquid used,it is desirable to switch the liquid to be overflowed to the water.

In addition, it is possible to supply the cleaning liquid whenperforming the ultrasonic cleaning of the nozzle 22, or to supply andstore the water when the cleaning is not performed for a long period oftime.

In addition, the cleaning liquid to be supplied to the cleaning tank1206 can be supplied after diluting original liquid which is in thecleaning liquid tank 1503 with the water.

FIG. 15 is an example of a processing flow of the nozzle cleaning inwhich the ultrasonic cleaner of the present invention is used. FIG.15(a) is a sampling processing flow of the sample including theultrasonic cleaning, FIG. 15(b) is a processing flow of the ultrasoniccleaning, and FIG. 15(c) is an replacement timing of the cleaningliquid, respectively.

At the time of S1601 in a state where the device is in an operationstate, the sample dispensing mechanism 15 repeats S1611 of the samplingprocessing with respect to the sample. In S1611 of the samplingprocessing, S1612 of dispensing (suctioning of the sample and ejectingof the sample) is not performed, and in a case where the sample to bedispensed is a sample which does not require the ultrasonic cleaning(S1613 of determination processing), S1614 of the water cleaning inwhich the nozzle 22 is washed with the water is performed, and in a caseof a sample which requires the ultrasonic cleaning (S1613 ofdetermination processing), the water cleaning is performed afterperforming S1615 (the processing flow will be described later in detail)of the ultrasonic cleaning. The above-described processing will berepeated.

In the description above, according to the result of S1613 of the sampledetermination, a case of only S1614 of the water cleaning processing anda case of S1615 of the ultrasonic cleaning and S1616 of the watercleaning are divided, but S1615 of the ultrasonic cleaning may beperformed every time when the sampling is performed.

In S1615 of the ultrasonic cleaning, S1621 (for example, applying a sinewave of predetermined voltage) of starting the driving of the ultrasonicvibrator (1201, 1301, 1401) is performed, S1622 of inserting the nozzle22 into the cleaning tank 1206, S1623 of drawing the nozzle 22 out ofthe cleaning tank 1206 after a certain period of time, and S1624 ofstopping the driving of the ultrasonic vibrator (1201, 1301, 1401), areperformed. After this, S1625 of replacing the cleaning liquid in thecleaning tank 1206 which is used in the cleaning by the overflow, isperformed.

The time period from S1622 of inserting the nozzle to S1623 of drawingout the nozzle is short in the middle of the operation, but the degreeof contamination can be estimated from the number of dispensations, andthe cleaning time can also be controlled to be long. In addition, in acase where the ultrasonic cleaning is performed in a maintenance statewhere the device does not require the dispensing processing, thecleaning time may be elongated.

Since the timing at which the heat radiation of the vibrating part (1202or 1303) is performed by the overflow of the liquid as described above,may be the timing at which a time 1631 when the S1615 of the ultrasoniccleaning is not performed is elongated, for example, a schedule in whichS1615 of the ultrasonic cleaning is not performed may be automaticallydetermined from the examination item or the type of the sample which ismanaged in the automatic analyzer 10, and the heat radiation of thevibrating part (1202 or 1303) may be performed by performing S1626 ofmaking the water overflowed. There is a method of performing S1626 ofmaking the water overflowed at the timing when the number of cleaningreaches the predetermined number in the middle of the operation, amethod of performing S1626 at a certain timing, or a method ofperforming S1626 when the temperature becomes equal to or higher than acertain temperature by temperature detection means. The temperaturedetection means will be described later.

In order to radiate the heat (cool) of the vibrating part (1202 or1303), after performing S1626 of making the water overflowed, S1627 ofthe processing of re-replace the cleaning liquid is performed, and S1615of the ultrasonic cleaning is performed.

FIG. 16 is a cleaning flow which corresponds to a change in thetemperature of the ultrasonic cleaner in the present invention. Thetiming of performing an ultrasonic cleaning 1700 is similar to S1615 ofthe ultrasonic cleaning. In S1700 of the ultrasonic cleaning, afterS1701 of starting the driving of the ultrasonic vibrator (1201, 1301,1401), S1702 of checking whether or not a difference between theresonance value of the ultrasonic vibrator (1201, 1301, 1401) and avalue measured in advance exceeds a predetermined threshold value, isperformed.

The resonance frequency can be output via a circuit (a circuit whichautomatically adjusts a frequency to that of a low frequency, andamplifies and outputs the voltage) which applies the voltage to theultrasonic vibrator. Therefore, the control portion 28 can ascertain thedifference by the resonance frequency output from the circuit, and it ispossible to determine that the difference exceeds the predeterminedthreshold value. The resonance frequency of the ultrasonic vibrator(1201, 1301, 1401) changes depending on the temperature, and when theresonance frequency changes to be greater than a value measured inadvance, it is possible to determined that the ultrasonic vibrator(1201, 1301, 1401) reaches a high temperature. The resonance frequencyof the ultrasonic vibrator (1201, 1301, 1401) used for comparison is,for example, stored in advance by a pre-operation when initiating theautomatic analyzer 10. When the ultrasonic vibrator (1201, 1301, 1401)reaches a high temperature, the heat radiation processing of thevibrating part (1202 or 1303) is necessary in order to prevent thenozzle 22 from being heated as described above. Here, in S1702 ofchecking the resonance frequency, in a case where the value which isgreater than threshold value is detected, the process is transited toS1703 of a state where the abnormality is detected before the cleaning,and the control portion stops the control of the dispensing nozzle whichis scheduled to be inserted into the cleaning tank. Additionally, analarm, such as displaying of the abnormality on an operation screen ofthe automatic analyzer 10, is notified to the user. Furthermore, S1704of overflow-cooling the above-described liquid by the overflow isperformed. It is desirable that S1704 of overflow-cooling (heatradiation operation) is performed for a certain period of time and theheat radiation is sufficiently performed.

In a case where a change is smaller than a threshold value in S1702 ofchecking the change in the resonance frequency of the vibrator, since itis possible to determine that the ultrasonic vibrator does not reach ahigh temperature as the change decreases, S1705 of inserting the nozzle22 into the cleaning tank 1206 is performed. After the nozzle 22 isinserted into the cleaning tank 1206 for a certain period of time andS706 of the ultrasonic cleaning, S1707 of drawing the nozzle 22 out ofthe cleaning tank 1206, S1708 of stopping the driving of the vibrator,S1709 of replacing the cleaning liquid, and S1710 of checking thetemperature of the nozzle, are performed. In addition, there is not aproblem even when S1708 of stopping the driving of the vibrator andS1710 of checking the temperature of the nozzle are performed at thesame time.

S1710 of checking the temperature of the nozzle can use temperaturemeasuring means, such as a temperature sensor which is sticked to thenozzle. In addition, a thermocouple is considered as a temperaturesensor. In addition, an infrared sensor may be used as the temperaturesensor, and it is possible to obtain the temperature of the nozzle in anon-contact manner by the infrared sensor. In addition, the temperatureof the nozzle 22 may be indirectly predicted from the temperature of thewater which washes the nozzle 22. The detection (or prediction) of thetemperature of the nozzle is not limited to the above-described meansand various means can be considered.

In a case where a difference between the temperature (or prediction oftemperature) of the nozzle 22 and the normal temperature is equal to orgreater than the threshold value, the process is transited to S1711 ofan abnormality state after cleaning the nozzle, and the control portionstops the control of a sample suction operation scheduled next.Additionally, as described above, in order to influence the dispensingaccuracy, the nozzle 22 itself is cooled (heat-radiated) by performingS1712 of performing the cleaning processing inside and outside thenozzle. In S1711 of the abnormality state after cleaning the nozzle, thealarm, such as the displaying of the abnormality on the operation screenof the automatic analyzer 10, may be notified to the user. By performingS1712 of performing the cleaning processing inside and outside thenozzle, the temperature of the nozzle 22 returns to the normaltemperature. In a case where there is not an abnormality in S1710 ofchecking the temperature of the nozzle, S1714 of continuing the samplingprocessing (S1611) is performed as usual after S1713 of the watercleaning of the nozzle 22.

S1702 of checking the change in the resonance frequency of theultrasonic vibrator can be switched to means for performing the checkingby the temperature sensor or the like.

According to the ultrasonic cleaner having the above-describedconfiguration, it is possible to make the influence of the temperatureof the ultrasonic vibrator which reaches a high temperature difficult tobe transmitted to the nozzle 22 by repeatedly cleaning the nozzle 22,and to clean the nozzle.

In the pipe connection (FIG. 14) of the present invention, the tubewhich passes through the cooler (for example, a reagent cold insulationbox) in a system which supplies the water is provided, and afterdetecting the temperature in the cleaning tank 1206, the cleaning liquidis mixed and diluted with the water cooled by the cooler, andaccordingly, control to an arbitrary liquid temperature is possible. Thechange in the liquid temperature after putting the liquid into thecleaning tank 1206 can be estimated from the measured value of thetemperature in the cleaning tank 1206, the temperature of the cleaningliquid can be controlled to be low in advance, and the cleaning liquidcan be supplied to reach the normal temperature in the cleaning tank1206.

In addition, the processing of FIGS. 15 and 16, and the checking and thecontrol of various sensors, are performed by the control portion 28.

Next, the effects of Example 4 will be described. The following effectscan be obtained in addition to the effects obtained by the vibratingpart of Example 3. First, by providing the heat radiation portionbetween the piezoelectric element (piezo element) and the vibratingpart, it is unlikely to transmit the influence of the temperature of thepiezoelectric element which reaches a high temperature due to therepeated cleaning of the nozzle 22, to the nozzle 22, and it is possibleto clean the nozzle.

In addition, in Example 3, regarding the heat radiation, the metal platespring disposed between the ultrasonic vibrator and the vibrating partand the cleaner base including the cleaning tank are fixed, and the heatradiation portion becomes the plate spring and the cleaner base. Inorder to improve the heat radiation effect, similar to Example 4, it isdesirable that the metal member disposed on a side closer to thepiezoelectric element than the vibrating part and the vibrator base arefixed, and the heat radiation portion becomes the metal member and thevibrator base. This is because the heat capacity of the metal member canbe greater than that of the plate spring.

In addition, it is desirable that a flow path for making the fluid flowin the ultrasonic vibrator is provided, and the heat radiation portionis a flow path. The heat of the piezoelectric element can be radiated bymaking the fluid flow in the flow path.

In addition, it is desirable that the pipe which is connected to thecleaning tank and supplies the cleaning liquid and the water isprovided, the control portion controls the supply of the cleaning liquidand the water to the cleaning tank via the pipe, the control portioncontrols the supply of the water to the cleaning tank at the timing whenthe driving control of the ultrasonic cleaner is not performed, and thewater is discharged from the opening part of the cleaning tank beingoverflowed. Accordingly, it is possible to effectively discharge theheat of the tip end of the vibrating part by the overflow. In addition,it is possible to discharge the heat with a small consumption amount ofthe cleaning liquid since not the cleaning liquid but the water is used.In a case where the cleaning liquid is detergent, an effect ofdecreasing the consumption amount of the cleaning liquid becomes a largeadvantage from the viewpoint of cost.

In addition, it is desirable that resonance frequency measuring meansfor measuring the resonance frequency of the ultrasonic vibrator isprovided, and in accordance with the resonance frequency measured by theresonance frequency measuring means, the control portion stops thecontrol of the dispensing nozzle which is scheduled to be inserted intothe cleaning tank. Accordingly, it is possible to estimate the heat ofthe ultrasonic vibrator by the resonance frequency, and to suppress theinsertion of the nozzle into the heated cleaning liquid. The resonancefrequency measuring means is, for example, a circuit itself whichapplies the voltage to the ultrasonic vibrator, and for example, whenthe resonance frequency changes to be greater than the value measured inadvance, it is possible to determine that the ultrasonic vibratorreaches a high temperature.

In addition, it is desirable that the temperature measuring means formeasuring the temperature of the dispensing nozzle is provided, and inaccordance with the temperature measured by the temperature measuringmeans, the control portion stops the control of a sample suctioningoperation which is scheduled next. Accordingly, it is possible todirectly or indirectly detect the temperature of the dispensing nozzleby the temperature measuring means, and to suppress the samplesuctioning operation by the heated dispensing nozzle. The temperaturemeasuring means may be, for example, the thermocouple or the infraredsensor which is sticked to the nozzle, or a sensor which detects thetemperature of the water which washes the nozzle, and may indirectlypredict the temperature of the nozzle from the detection value of thesensor. For example, in a case where the difference between thetemperature detected by the temperature sensor and the normaltemperature is equal to or greater than the threshold value, the controlis stopped. Accordingly, it is possible to suppress the negativeinfluence on the dispensing accuracy due to the heat of thepiezoelectric element.

In addition, it is desirable that any measuring means among theresonance frequency measuring means for measuring the resonancefrequency of the ultrasonic vibrator or the measuring means formeasuring the temperature of the dispensing nozzle is provided, and inaccordance with the measurement result of the measuring means, the heatof the dispensing nozzle is radiated by bringing inner cleaning waterand outer cleaning water into contact with the dispensing nozzle.Accordingly, the heat radiation of the dispensing nozzle is performed,and it is possible to suppress the negative influence on the dispensingaccuracy caused by the heat of the piezoelectric element.

Example 5

Next, another structure of the ultrasonic cleaner 26 will be described.The ultrasonic cleaner 26 generates the ultrasonic wave in the cleaningtank. As will be described later, the ultrasonic cleaner 26 is providedwith the vibrating part which is inserted into the cleaning liquid inthe cleaning tank and transmits the ultrasonic vibration to the cleaningliquid, and the ultrasonic vibrator which is configured by fixing andfastening the piezoelectric element with two or more metal blocks by thebolt, and generates the ultrasonic vibration to the vibrating part.

In Example 5, by the configuration of the ultrasonic cleaner in whichthe BLT is used, the ultrasonic cleaner which can increase the liquidtemperature of the cleaning liquid and obtain a high cleaning effect inaddition to the configuration in which strong cavitation which can cleanthe nozzle tip end (in particular, outer circumference) withoutunevenness at a range of 20 to 100 kHz of the driving frequency, will bedescribed.

However, the cleaning effect can be roughly divided into the cleaningwhich uses a chemical effect of the cleaning liquid and the cleaningwhich uses a physical effect, such as cavitation or a straight flow, andin order to obtain a strong cleaning effect, it is required to use bothcleaning manners. Regarding the physical effect of the cleaning, it ispossible to generate the strong cavitation by generating a largedisplacement. Regarding the chemical effect of the cleaning, it iseffective to select an appropriate type of the cleaning liquid, and tocontrol the liquid temperature. In particular, a high cleaning effectcan be obtained by increasing the liquid temperature with respect to thecontaminants including protein, such as blood.

FIG. 17 is a view illustrating an example of the configuration of theultrasonic cleaner of present invention. FIG. 17(a) is an upper view,FIG. 17(b) is a side view, FIG. 17(c) is a sectional view, and FIG.17(d) is a perspective view (section taken along A-A of the upper view(a)) of the ultrasonic cleaner, respectively. The ultrasonic cleaner 26includes an ultrasonic vibrator (BLT) 2205 and a vibrating part(cleaning head) 2209. The ultrasonic vibrator (BLT) 2205 is configuredby interposing one or more piezoelectric elements 203 between a frontmass 2201 and a back mass 2202, and by fastening the front mass 2201 andthe back mass 2202 by a bolt 2204. A base portion 2207 which is a partof the automatic analyzer includes a cleaning tank 2206 in which thecleaning liquid is stored, and supports an ultrasonic vibrator 2205. Theultrasonic vibrator 2205 is provided with a flange portion 2208, and issupported by the base portion 2207 via the flange portion 2208.Furthermore, the ultrasonic vibrator 2205 is connected to the vibratingpart (cleaning head) 2209 which extends to the cleaning tank 2206.

A tip end part 2210 of the vibrating part (cleaning head) 2209 has acylindrical shape, and is in a state of being inserted into the cleaningliquid, and a part or the entirety of the cylindrical shape is immersed.In other words, the vibrating part (cleaning head) 2209 has a shape ofsurrounding the nozzle similar to the cylindrical shape. The tip endpart 2210 is not in contact with the cleaning tank 2206. In thecylindrical part of the tip end part 2210, a hole having a diametergreater than that of the tip end of the nozzle 22 is open. Therefore,the vibrating part (cleaning head) 2209 has a hollow part (nozzleinsertion port 303 which will be describe later), the nozzle 22 can beinserted into the hollow part, and the hollow part is filled with thecleaning liquid. The control portion 28 performs the cleaning of thenozzle 22 by vibrating the vibrating part (cleaning head) in a statewhere the nozzle 22 is inserted into the hollow part.

In addition, a cleaning liquid supply tube 2211 which supplies thecleaning liquid to the cleaning tank 2206 is provided, and it ispossible to replace the cleaning liquid which is in the cleaning tank2206 by the overflow by supplying a certain amount of cleaning liquid.The cleaning liquid overflowed from the cleaning tank 2206 flows to aliquid receiver 2212 which is on an outer circumference of the cleaningtank 2206, and is discharged from a drainage path 2213. Here, it isdesirable that an outlet on the cleaning tank 2206 side of the cleaningliquid supply tube 2221 is disposed immediately below the bottom of thevibrating part as illustrated in the drawing. This is because it ispossible to prevent the cleaning liquid from being flown out of thecleaning tank by making the cleaning liquid abut against the bottom ofthe vibrating part in a case where the cleaning liquid is forcefullysupplied. Accordingly, it is possible to forcefully supply the cleaningliquid into the cleaning tank while preventing the cleaning liquid frombeing flown out of the cleaning tank, and to replace the cleaning liquidduring a short period of time. In addition, in the vibrating part ofFIG. 10, similarly, it is also desirable that the outlet of the liquidfeeding port is disposed immediately below the vibrating part.

In addition, in the drawing, a view in which only a lower side of theflange portion 2208 is supported by the base portion 2207 is described,but it is desirable that the upper side of the flange portion 2208 ispressed from above by a member which can connect the upper side to thebase portion 2207, and the entire circumference of the flange portion2208 is equivalently fixed. In addition, an interference member havingan elastic force, such as rubber or silicon, may be put into the part atwhich the flange portion 2208 and the base portion are in contact witheach other for preventing wear or noise of the flange portion 2208 orthe base portion 2207.

In addition, the front mass 2201 and the back mass 2202 are metalblocks, an electrode plate (for example, a copper plate) is interposedbetween the metal block (2201 or 2202) and a piezoelectric element 2203,and between the plurality of piezoelectric elements 2203, and byapplying the sine wave voltage of an arbitrary frequency to theelectrode, the ultrasonic vibrator 2205 is driven in the shaft directionof the bolt 2204. In addition, this is a merely an example, and onepiezoelectric element 2203 may be provided. In the ultrasonic vibrator2205, the number of piezoelectric elements does not matter as long as astructure in which the piezoelectric element is fixed by fastening twoor more metal blocks by the bolt. As the ultrasonic vibrator 205 isdriven in the shaft direction of the bolt 2204, it is possible togenerate the ultrasonic vibration to the vibrating part (cleaning head)2209.

In particular, by making the shape of the front mass 2201 as a shape ofa horn (a shape whose diameter on the piezoelectric element 2203 sideand on the tip end side changes) as illustrated in the drawing, it ispossible to amplify the generated amplitude of the piezoelectric element2203. By designing the length or the shape of the horn in accordancewith the frequency which is desired to be driven, a large amplitude canbe obtained by a small amount of electricity. In FIG. 17, a shape of aconical horn is illustrated, but other shapes (exponential horn or thelike) also do not have a problem. In other words, the diameter of themetal block to which the vibrating part is fixed continuously decreaseswhen approaching the vibrating part. In addition, the sectional shape ofthe shape of a horn may not be circular, and may be polygonal. In thiscase, the diameter of a circumscribed circle and an inscribed circlecontinuously decreases. In addition, regarding the fixing of thevibrating part, since the vibrating part may be integrated with thefront mass 2201, the fixing may be performed by the bolt or the like, orthe vibrating part may be formed as one component with the front mass2201.

Furthermore, in the example, the elongated vibrating part (cleaninghead) 2209 which extends to the cleaning tank 2206 is provided at thetip end of the front mass 2201 having a shape of a horn, the vibrationof the tip end of the horn is further enlarged by bending the memberwhich extends downward, and a large displacement can be generated in thetip end part 2210.

In the ultrasonic cleaner 26 having the above-described configuration,by driving (generating the ultrasonic vibration) the piezoelectricelement 2203 at a frequency of 20 to 100 kHz, the vibrating part(cleaning head) 2209 in the cleaning tank 2206 vibrates (the frequencyis the same as the driving frequency) by a large displacement, and thecavitation occurs at the center of the periphery of the tip end part2210 which is immersed in the cleaning liquid.

When cleaning the nozzle 22 by the ultrasonic cleaner 26, thepiezoelectric element 2203 is driven at a frequency of 20 to 100 kHz,the nozzle 22 is inserted into the hole (hollow part) on the inner sideof the cylindrical shape of the tip end part 2210 so that the cleaningrange (range of approximately 5 millimeters from the nozzle tip end) isimmersed in the cleaning liquid, and the contaminants which adhere tothe outer circumferential part of the nozzle is removed by thecavitation by bringing the nozzle 22 in contact with the cleaning waterfor a certain period of time. The ultrasonic cleaner 26 of the presentinvention can generate a strong cavitation by a displacement enlargingeffect of the vibrating part (cleaning head) 2209.

Additionally, when the ultrasonic vibrator 2205 vibrates, the vibratingpart (cleaning head) 2209 has a resonance point at which the vibratingpart (cleaning head) 2209 inserted into the cleaning tank 2206 resonatesand vibrates within a range of 20 to 100 kHz. In addition, the controlportion 28 cleans the nozzle 22 by vibrating the vibrating part(cleaning head) 2209 at 20 to 100 kHz in a state where the nozzle isinserted into the hollow part. Therefore, the tip end part 2210 canresonate in synchronization with the vibration of the ultrasonicvibrator 2205, and it is possible to effectively convert electric energyapplied to the ultrasonic vibrator 2205 into a large amplitude of thetip end part 2210. In general mechanical design, since the bending isamplified as the components resonate each other, resonance points foravoiding the damage of the component can be designed to be separated,but the vibrating part (cleaning head) 2209 can obtain a high cleaningeffect during a short period of time by actively using a resonancephenomenon on purpose since it is assumed that continuous driving for along period of time is not performed.

After the cleaning, by drawing out the nozzle 22 and automaticallyreplacing the cleaning liquid by the overflow, it is possible to performthe cleaning with new cleaning liquid when cleaning the next nozzle 22,and to suppress the carry-over.

In addition, since the cleaning can be performed as long as thecylindrical hole of the tip end part 2210 and the cleaning liquid on theperiphery thereof are present, it is possible to reduce the amount ofthe cleaning liquid to be used. For example, when the outer diameter ofthe narrow nozzle is equal to or less than 1.0 millimeters, it ispossible to perform the cleaning even when the liquid amount is equal toor less than 0.5 mL, and it is also possible to reduce the size of thecleaner.

Furthermore, by using the liquid temperature control which will bedescribed later, it is possible to achieve a liquid temperature(temperature higher than the normal temperature) having a high effect ofthe chemical action of the cleaning liquid, and to obtain a highcleaning effect during a short period of time by a contaminant removingaction by the physical action and the chemical action caused by thestrong cavitation.

In the example, a method of use in which the cleaning liquid is put intothe cleaning tank 2206 is described, but the cleaning liquid is notlimited to the detergent, and may be the water. Even when the water isused, the fact that a high cleaning effect can be obtained by thecavitation does not change, not only the detergent but also hot water iseffective with respect to the contaminants, such as protein, and thewater may be used according to the target cleaning effect.

FIG. 18 is an example of a structure of the vibrating part (cleaninghead) 2209 of the ultrasonic cleaner 26 of the example. Hereinafter, thevibrating part will be referred to as the cleaning head 2209. FIG. 18(a)is a front view, FIG. 18(b) is a side view, FIG. 18(c) is a perspectiveview of the cleaning head 2209, FIGS. 18(d), 18(e), and 18(f) areexamples of other shapes of the tip end shape, FIG. 18(g) is an examplein which the processing is applied to the neck, and FIG. 18(h) is anexample in which a round part (R part) is provided between a tip end anda root. In addition, a neck 2304 is included in the cleaning head 2209in addition to the tip end part.

Since it is necessary to attach the cleaning head 2209 to the tip end ofthe ultrasonic vibrator 2205, or to make an integrated structure withthe front mass 2201, a fixing portion 2301 positioned in the upper partof the cleaning head 2209 is a columnar shape (an inclination may beprovided on the side surface in accordance with the shape of a horn ofthe front mass 2201). A cleaning portion 2302 is provided in the tip endpart of the lower part of the cleaning head 2209. In the cleaningportion 2302, a nozzle insertion port (through hole) 2303 which has theabove-described cylindrical shape, which is greater than an outer shapeof the nozzle 22 that is the cleaning target on the inner side of thecylindrical shape, and which corresponds to the hollow part. Between thefixing portion 2301 and the cleaning portion 2302, the neck 2304 forenlarging the displacement of the cleaning portion 2302, and areinforcing portion 2305 which links the neck 2304 to the fixing portion2301 and increases the strength of the root part, are provided. Sincethe neck 2304 extends in the perpendicular direction and the nozzle islowered in the perpendicular direction and is inserted into the hollowpart, the interference of the neck 2304 and the nozzle 22 is avoided.Therefore, the cleaning portion 2302 protrudes in the horizontaldirection with respect to the neck 2304 (similar to the drawing, theside surface has an L shape).

In addition, the length from the end surface of the neck 2304 to the tipend of the cleaning portion 2302 in the horizontal direction is definedas a length 2302 a of the cleaning portion, and the length from thelower end of the reinforcing portion 2305 to the lower end of thecleaning portion 2302 in the perpendicular direction is defined as alength 2304 a of the neck portion. In addition, a height 2302 b of thecleaning portion is defined by the shape of the cleaning portion 2302.

Since the cleaning portion 2302 is immersed in the cleaning liquidstored in the cleaning tank 2206 as described above, by driving thepiezoelectric element 2203, the cavitation occurs in the cleaning liquidin the nozzle insertion port 2303 by the enlarged vibration in thecleaning portion 2302. In particular, the displacement generated in thepiezoelectric element 2203 is enlarged by the front mass 2201 having theabove-described shape of a horn, and is also further enlarged by theneck 2304. Therefore, the vibration of the large displacement isachieved in the cleaning portion 2302. Since the cavitation occurs inthe region in which the ultrasonic wave is concentrated, and thecavitation becomes stronger as the ultrasonic intensity becomesstronger, the generation of a large displacement in a narrow range iseffective in making the cavitation occur. In the cleaning head 2209 ofthe present invention, the large displacement can be generated, andfurther, the nozzle insertion port 2303 which matches the size of thenozzle 22 is a narrow region in which the hole diameter can be equal toor less the several millimeters, the distance between a vibrationgenerating surface having high strength of cavitation and the entirecircumference of the nozzle 22, and strong cavitation can be emitted. Inaddition, the cavitation becomes stronger as the nozzle insertion port2303 becomes smaller, but as described above, there is a problem ofresidual vibration for the nozzle 22 to move at high speed, and it isnecessary to design the nozzle insertion port 2303 to have a tolerancein a range with which the nozzle 22 is not in contact at the residualvibration generated in the lowering operation of the nozzle 22.Additionally, the cleaning portion 2302 has the resonance point when theultrasonic vibrator 2205 vibrates within a range of 20 to 100 kHz. Sincethe ultrasonic vibrator 2205 vibrates at 20 to 100 kHz, a structureitself of the cleaning head 2209 is a structure which easily resonates.It is possible to emit strong cavitation by the resonance effect duringa short period of time.

Next, an example of another shape of the cleaning portion 2302 will bedescribed. As the shape of the cleaning portion 2302, a rectangularblock shape 2311 having a notch, a cylindrical shape 2312 having anotch, or a shape 2313 in which a prismatic hole is open, also canobtain the cleaning effect. The attaching direction of each shape (2302,2311, 2312, 2313) of the cleaning portion does not matter. For example,when the cleaning portion (2302, 2311, 2312, 2313) are attached beingshifted by 90 degrees in the shaft direction of the bolt 2204, thecleaning can also be performed. In addition, the nozzle insertion port2303 of the example of another shape can also be considered as thehollow part. In this manner, as the shape of the cleaning portion 2302,any of a shape having a notch and a shape which completely surrounds thenozzle may be employed. In other words, when the part of the cleaningportion 2302 is disposed in the plural directions when viewed from thenozzle 22, the part can be considered as the hollow part. By configuringthe cleaning portion 2302 in this manner, it is possible to suppress thecleaning unevenness.

In the neck 2304, processing 2320 in which the diameter of the neck isnarrow order to make it easy to enlarge the amplitude of the cleaningportion 2302 (in order to generate distortion which will be describedlater), may be added.

A cleaning head 2314 is an example of a structure different from thecleaning head 2209. In the cleaning head 2314, similar to the cleaninghead 2209, the fixing portion 2301, the cleaning portion 2302, and theneck 2304 are provided (the reinforcing portion 2305 is not provided).The cleaning head 2314 is different from the cleaning head 2209 in thatthe nozzle insertion port 2303 is positioned to be comparativelyseparated from the neck 2304 by providing a connection portion 2321between the cleaning portion 2302 and the neck 2304. An advantage of thecleaning head 2314 is that it is possible to provide the round part (Rpart) in the connection portion 2321, and to disperse stress generatedat the large vibration of the cleaning portion 2302. Durability canincrease by dispersing the stress and the use period can extend. Inaddition, as the nozzle insertion port 3032 is separated from the neck2304, it is possible to further reduce a contact risk of the nozzle 22and the cleaning head 2314. By attaching the cleaning head 2209 havingthe above-described configuration to the above-described ultrasonicvibrator 2205, or by making the front mass 2201 in an integratedstructure, it is possible to cause the cavitation which occurs in thenozzle insertion port 2303 to effectively act on the outer circumferenceof the nozzle 22 which is inserted into the nozzle insertion port 2303and immersed in the cleaning liquid.

FIG. 19 is a view illustrating an example of a vibration mode of thecleaning head 2209 and a temperature gradient of the cleaning liquid.FIG. 19(a) is deformation of a primary vibration mode, FIG. 19(b) isdeformation of a secondary vibration mode, FIG. 19(c) is a temperaturegradient of the cleaning liquid, and FIG. 19(d) is an impedance waveformof the ultrasonic vibrator to which the cleaning head (2209, 2314) isattached, respectively.

As described above, in the cleaning head 2209, the elongated neck 2304is provided, and the vibration of the cleaning portion 2302 of the tipend is enlarged. The resonance frequency of the cleaning head 2209 isdetermined by a material (Young's modulus) of the cleaning head 2209,the length and the sectional shape of the neck 2304, and by the mass ofthe cleaning portion 2302, and the vibration of the cleaning portion2302 becomes a large amplitude by performing the driving using theresonance frequency. In addition, a plurality of resonance frequenciesin the shape added by the mass similar to the cleaning portion 2302 areprovided at the tip end, and for example, in the cleaning head 2209, theresonance frequency in which the deformations, such as the primaryvibration mode (a) and the secondary vibration mode (b), are generated.In addition, (a) and (b) illustrate the deformations of the neck 2304 byextremely enlarging the deformations in order to easily understand thedifference of the vibration modes.

The primary vibration mode is a vibration mode in which the cleaningportion 2302 largely vibrates in the shaft direction of the bolt 2204.The secondary vibration mode is a vibration mode in which the cleaningportion 2302 vibrates in the shaft direction of the bolt 2204, a node (apart at which the amplitude is small) of the vibration is possible inthe middle of the cleaning portion 2302, and the upper part and thelower part largely vibrate. Regarding the cleaning performance, in anyvibration mode, the amplitude of the cleaning portion 2302 is obtainedand the cavitation can occur, but in the secondary vibration mode, theupper and lower parts of the cleaning portion 2302 vibrate horizontallyin the opposite phase around the node. Therefore, the movement of thecleaning portion 2302 for shaking the cleaning liquid generates a waterflow in the cleaning tank 2206, the contaminants of the nozzle 22 whichare dropped by the cavitation circulate in the cleaning tank 2206, andre-adhesion to the nozzle 22 can be suppressed. Meanwhile, the amplitudein the primary vibration mode can be greater than that in the secondaryvibration mode.

Since the cleaning portion 2302 largely vibrates in the primaryvibration mode, the neck 2304 is deformed and the distortion isgenerated. In the secondary vibration mode, since the vibration whichbecome the opposite phase on the upper surface and on the lower surfaceof the cleaning portion 2302 causes the movement, the distortion isgenerated in the vicinity of a connecting part between the neck 2304 andthe cleaning portion 2302. Since the metal material generates the heatwhen the distortion is generated, the heat is generated at a part nearthe cleaning portion 2302 of the neck 2304 in the primary vibrationmode, and the heat is generated in the vicinity of the connecting partof the cleaning portion 2302 in the secondary vibration mode. Since theheat is generated at the part near the cleaning tank 2206 in any cases,the heat of the cleaning head 2209 moves to the cleaning liquid from thecleaning portion 2302. In particular, since the hole is open in thecleaning portion 2302 as described above, the contact area with thecleaning liquid increases, and the heat can effectively move. On thecontrary, the reinforcing portion 2305 or the fixing portion 2301 whichhas a large volume is provided at the upper part of the cleaning head2209, and the heat is more unlikely to be transmitted to thepiezoelectric element 2203 than to the cleaning liquid since the heat isscattered. In addition, the heat can be discharged from the cleaningportion 2302 by performing the overflow of the cleaning liquid, theultrasonic cleaner 26 also can prevent the heat generation having atemperature which is equal to or higher than a certain temperature evenwhen the cleaning operation is continuously performed, and it ispossible to use the cleaning liquid having a high liquid temperaturewhich does not exceed a high temperature only in a time zone where thenozzle 22 is cleaned.

In addition, since the distortion is easily generated at a step part, ina case where the heat is not desired to be generated, it is possible tosuppress the distortion by performing round processing (R processing) atthe step part (refer to the R part of the cleaning head 2314). Inparticular, when the distortion is generated at the root part of theneck 2304, the root part is far from the cleaning tank 2206, and thetransmission efficiency to the cleaning liquid is not excellent comparedto a case where the heat is generated in the cleaning portion 2302.Therefore, it is desirable that the connection part between thereinforcing portion 2305 and the neck 2304 has a shape in which theround processing (R processing) is performed and a rapid change in theshape is not generated.

A temperature gradient 2401 of the cleaning liquid in the cleaning tank2206 when the cleaning head 2209 is operated (when the ultrasonicvibrator 2205 is driven) is linearly raised for a certain period oftime, and starts to be saturated after the certain period of time (referto (c)). Therefore, the increase in liquid temperature from the start ofthe driving after the certain period of time can be illustrated by alinear approximate line 2402. As described above, the liquid temperatureis lowered by making the cleaning liquid overflowed, but the temperaturegradient 2401 can similarly raise the liquid temperature withoutdiffering from before the overflow. In other words, the temperaturegradient of the liquid temperature in the cleaning tank 2206 when thecleaning head 2209 is operated again is investigated, and further, it ispossible to predict the liquid temperature after the operation for acertain period of time when the liquid temperature before the operationof the cleaning head 2209 is known.

However, when using the primary vibration mode of the cleaning head2209, the vibration amplitude becomes the maximum in the vicinity of thelower part of the cleaning portion 2302, and a state where the tip endpart of the nozzle 22 can be cleaned the most is achieved. Meanwhile,when the second vibration mode of the cleaning head 2209 is used,regarding the vibration amplitude, the amplitude becomes the maximum inthe vicinity of the upper part and the lower part of the cleaningportion 2302, and thus, the vibration mode is properly used according tothe point which is desired to be cleaned in the nozzle 22, andaccordingly, it is possible to obtain a high cleaning effect. Forexample, when suctioning the liquid from the container into which theliquid is put using the nozzle 22, the contaminants are likely to beaccumulated at a position which is the same as the liquid surface of thenozzle 22 due to the surface tension of the liquid. Here, in a casewhere the driving is performed in the secondary vibration mode of theabove-described cleaning head 2209, by matching the position (positionwhich is the same as the liquid surface when suctioning the liquid) atwhich the contaminants of the nozzle 22 are accumulated to the height ofthe upper part of the cleaning head 2209, the contaminants can be easilyremoved. In other words, not only at the tip end of the nozzle 22, butalso at the upper part thereof, it is possible to perform the cleaningwith a strong cleaning force.

FIG. 19(d) is a view illustrating a frequency in a horizontal axis andan impedance in a vertical axis. A resonance point 2410 of the vibratinghead and a resonance point 2411 (a mode of stretching and contractingthe bolt 2042 in the shaft direction) of the ultrasonic vibrator 2205are illustrated.

The cleaning head 2209 (314) can increase the cleaning force in thedriving of the primary vibration mode and in the driving of thesecondary vibration mode by a structure in which the resonance point ispresent at the driving frequency of 20 to 100 kHz in the ultrasonicvibrator 2205.

In particular, as illustrated in FIG. 19(d), it is desirable that theresonance point 2410 (a mode in which the tip end largely vibrates asillustrated in FIGS. 19(a) and 19(b)) of the cleaning head, and theresonance point 2411 of the ultrasonic vibrator 2205, approach eachother, and an absolute value of the difference of the values is designedto be equal to or less than 10 kHz. The resonance point 2410 may be anyof a resonance point of the primary vibration mode and a resonance pointof the secondary vibration mode.

Whether performing the driving in the primary vibration mode or in thesecondary vibration mode is determined by the structure of the cleaninghead 2209 (2314). In particular, due to the condition of forming thehollow part, the cleaning head 2209 (2302) has a structure of thecleaning head 2209 (2314) having a weight at the tip end of the neck.When the neck is elongated or the weight is given to the tip end, theresonance point of the primary vibration mode tends to have a lowfrequency. Therefore, in a case where the primary vibration mode isdesired to be used, it is necessary to consider the length or the weightof the neck. This is because the resonance point of the primaryvibration mode of the cleaning head becomes less than 20 kHz when notconsidering the length or the weight of the neck. In addition, on thecontrary, by employing an appropriate length or an appropriate weight ofthe neck, it is possible to include the resonance point of the primaryvibration mode or the secondary vibration mode within the range of 20 to100 kHz. In addition, since parameters which influence the resonancepoint are various as will be described later, here, the representativeparameters, such as the length of the neck and the weight of the tip endare focused.

As described above, by performing the driving in a vibration mode inwhich the cleaning portion 2302 vibrates, the heat can be generated at apart close to the cleaning tank 2206 of the cleaning head 2209, and theliquid temperature of the cleaning liquid in the cleaning tank 2206 canbe raised. In other words, before inserting the nozzle 22 into thecleaning liquid in the cleaning tank 2206, by driving the ultrasoniccleaner, the temperature of the cleaning liquid in the cleaning tank2206 becomes a temperature higher than the normal temperature, thenozzle 22 is inserted into the cleaning liquid of the temperature higherthan the normal temperature, and the ultrasonic cleaning is performed.In addition, when the gradient of the raising temperature per unit timeis known in advance, it is possible to predict the liquid temperatureafter a certain period of time.

In addition, in using the secondary vibration mode at 20 to 100 kHz bythe cleaning head 2209 (2314), it is necessary to appropriately designthe rigidity of the neck determined by the length 2304 a, the width (thediameter of the neck in the cleaning head 2209), and the depth (diameterof the neck in the cleaning head 2209) of the neck, and the mass of thecleaning portion 2302 which is determined by the length 2302 a of thecleaning portion, the inner diameter of the nozzle insertion port 2303,and the outer diameter of the cleaning portion 2302.

It is necessary to narrowly design the outer diameter of the tip end ofthe nozzle 22 which is a target of the example to be 0.5 to 1.5 mm, andto design the nozzle insertion port 2303 to match the outer diameter ofthe nozzle. For example, the inner diameter of the nozzle insertion port2303 is designed to be 2.0 to 4.0 mm, the height 2302 b of the cleaningportion is designed to be 4.0 mm when the tip end of the nozzle 22becomes 4.0 mm in the cleaning range, the thickness and the depth of theneck is designed to be in a range of 3.0 to 5.0 mm in the cleaning head2314, the length is designed to be in a range of 15 to 20 mm, and thelength 2302 a of the cleaning portion is designed to be in a range of 7to 10 mm. Accordingly, a design in which the resonance point of thesecondary vibration mode is present at approximately 20 to 100 kHz, isemployed. In the cleaning head 2209, the above-described thickness andthe depth part of the neck is changed to the diameter, and is set to be3.0 to 5.0 mm.

By considering the above-described dimensions as a reference, using theanalysis, such as a finite element method, the design of the resonancefrequency is performed more specifically. In addition, since therigidity of the neck 2304 changes according to the presence or theabsence of the R part 2321 between the cleaning portion 2302 and theneck 2304, and the shape of the round part (R part), there is also acase where the design condition of the resonance frequency is shifted byapproximately ±1 mm from the reference dimension. In the example, anexample in which the nozzle insertion port 2303 is near the tip end sideof the cleaning portion 2302 is illustrated, but in a case where thenozzle insertion port 2303 is near the neck 2304 side, the center ofgravity varies, and thus, the resonance frequency is slightly shifted.

In addition, the cleaning head (2209, 2314) is designed in a range ofbeing shifted from the above-described dimension according to the outerdiameter of the nozzle 22, but in designing the resonance of thesecondary vibration mode to be 20 to 100 kHz, it is possible tosimilarly design from a ratio of the above-described rigidity of theneck and the cleaning portion.

It is desirable that the material of the cleaning head (2209, 2314) issimilar to the material of the front mass 2201, or the material is SUSor titanium.

In this manner, in the description above, an example of the shape havingthe resonance point of the secondary vibration mode in 20 of 100 kHz isillustrated, but not being limited to the above-described numericalrange, it is possible to have the resonance point of the secondaryvibration mode in the above-described range, and thus, each numericalvalue itself is not important in a specific shape, and it is possible torealize the secondary vibration mode in various numerical values. Thecontrol portion 28 can obtain an effect obtained in the above-describedsecondary vibration mode by vibrating the ultrasonic vibrator at afrequency at which the cleaning head (2209, 2314) vibrates in thesecondary vibration mode, and by performing the cleaning of the nozzle.

FIG. 20 is an example of a time chart of the nozzle cleaning during theoperation in which the ultrasonic cleaner of the example is used. InFIG. 20, a time chart of a nozzle operation, an operation of theultrasonic vibrator, and replacing of the cleaning liquid, areillustrated, and a temporal change in the temperature of the cleaningliquid is also illustrated. During the operation, since the device isoperated at a high throughput for the sample examination, it isnecessary to perform the cleaning of the nozzle 22 during a short periodof time. For example, the cleaning of the nozzle is performed within 3.6seconds. In addition, the operations are controlled by the controlportion 28.

First, in order to replace the cleaning liquid in the cleaning tank2206, a certain amount of cleaning liquid is extruded, and the overflow(2501) is performed. The cleaning liquid is extruded by the pump whichis connected to the cleaning liquid supply tube 2211. After replacingthe cleaning liquid and suppressing fluctuation of the liquid surface,the ultrasonic vibrator is driven, and the ultrasonic vibration isgenerated with respect to the cleaning liquid in the cleaning tank 2206(2502). By generating the ultrasonic vibration, as described above, thecavitation occurs in the cleaning liquid in the cleaning tank 2206.

Next, the nozzle 22 is inserted into the cleaning liquid in the cleaningtank 2206 after the generation of the ultrasonic wave (2503), and thenozzle 22 is drawing out of the cleaning tank 2206 after a certainperiod of time (2504). An operation of inserting the nozzle 22 to thecleaning liquid in the cleaning tank 2206 (2503) and an operation ofdrawing the nozzle 22 out of the cleaning liquid (2504), are performedin the vertical operation of the sample dispensing mechanism 15 asdescribed above, and the time period during which the nozzle 22 isimmersed in the cleaning liquid in the cleaning tank 206 becomes thecleaning time at which the ultrasonic cleaner 26 is used.

In addition, after drawing out the nozzle 22, by stopping the ultrasonicvibration (2505) and by making the cleaning liquid overflowed (2506)again for the next cleaning, it is possible to perform the next cleaningwith new cleaning liquid, and the contaminants of the nozzle 22 whichare dropped by the ultrasonic cleaner 26 are discharged from the deviceas waste water.

In addition, the replacement timing of the cleaning liquid may be atiming immediately before using the ultrasonic cleaner 26 next, or maybe a timing immediately after using the ultrasonic cleaner 26.

When performing the cleaning operation at the timing illustrated in FIG.20, the temperature (2520) of the cleaning liquid in the cleaning tank2206 is transited as illustrated in FIG. 20. The liquid temperature islowered after the overflow (2501) of the cleaning liquid, and at atiming (2510) of starting the ultrasonic vibration for cleaning thenozzle 22, the liquid temperature starts to be raised by a certaingradient, and the temperature continues to be raised until a timing(2513) of stopping the ultrasonic vibrator. The liquid temperature islowered after the timing, and the liquid temperature is further loweredby making the cleaning liquid overflowed (2506).

The ultrasonic cleaner 26 of the example can control the liquidtemperature at the timing of cleaning the nozzle 22 to be a temperaturewhich is appropriate in the cleaning. As described above, it isascertained that the cleaning head 2209 (2314) of the ultrasonic cleaner26 generates the heat at the neck of the cleaning head by the vibration,and the increase in the liquid temperature linearly changes during acertain period of time. Therefore, by adjusting an interval (time)between the timing (2510) of starting the ultrasonic vibration and thetiming (2511) of inserting the nozzle 22 into the cleaning liquid in thecleaning tank, it is possible to control the liquid temperature of thecleaning liquid in the cleaning tank 206 of the timing (2510) ofstarting the ultrasonic vibration to be an arbitrary liquid temperature.

When setting the timing (2510) of starting the ultrasonic vibration tobe earlier, compared to the time when the operation is performed at thereference timing, the liquid temperature during the cleaning canincrease. On the contrary, when setting the timing (2510) of startingthe ultrasonic vibration to be later, compared to the time when theoperation is performed at the reference timing, the liquid temperatureduring the cleaning can decrease. In this manner, the temperature changewhich is different from the temperature change illustrated in FIG. 20can be realized by the adjustment of the start timing of the ultrasonicvibration.

Here, since the nozzle 22 thermally expands when being immersed in theliquid having a high temperature, and the thermal expansion negativelyinfluences the dispensing accuracy, the liquid temperature in thecleaning tank 2206 is not limited, the high temperature is notnecessarily appropriate, and the liquid temperature which is in a rangeof not influencing the dispensing accuracy, is higher than the normaltemperature (approximately 25° C.), and which can improve the cleaningeffect, should be employed. In other words, only by simply setting thetiming (2510) of starting the ultrasonic vibration to be earlier, thedispensing accuracy deteriorates even when the cleaning effect of thenozzle 22 is obtained, and a sufficient performance as the analyzercannot be realized.

For example, when the liquid temperature (for example, equal to orhigher than 60° C.) which influences the dispensing accuracy is set withrespect to the liquid temperature (for example, equal to or higher than40° C.) at which the cleaning effect is high, if the temperature doesnot reach 60° C. or higher until the timing (2512) of drawing the nozzle22 out of the cleaning liquid in the cleaning tank 2206, the temperaturedoes not influence the dispensing accuracy, and if the temperature isequal to or higher than 40° C. until the timing (2511) of inserting thenozzle 22 into the cleaning liquid in the cleaning tank 2206, thecleaning effect which is higher than that of the cleaning liquid at thenormal temperature (approximately 25° C.) is obtained. Therefore, whenthe liquid temperature of the timing (2510) of starting the ultrasonicvibration is, for example, 25° C., and the temperature gradient of thecleaning liquid confirmed in advance is, for example, 3° C./seconds, theliquid temperature after 5 seconds becomes 40° C., and the liquidtemperature after 12 seconds becomes 61° C. Therefore, the ultrasonicvibrator may be driven 5 or more seconds ago of 2503 of inserting thenozzle 22 into the cleaning liquid in the cleaning tank, and theultrasonic vibration may be generated (502). As described above, sincethe automatic analyzer is a device which is operated at a highthroughput, and the cleaning time of the nozzle 22 can be ensured onlyfor approximately several seconds, if the nozzle 22 is inserted into thecleaning tank (2503), and the liquid temperature is 40° C. to 50° C.,even when the liquid temperature increases during the cleaning, thetemperature does not become equal to or greater than 60° C., and thereis not the influence on the dispensing accuracy.

When an operation pattern is set after considering all of theconditions, while removing the influence on the dispensing accuracy inone operation pattern, it is possible to realize the cleaning at theliquid temperature having a high cleaning effect. However, when thevolume of the cleaning liquid in the cleaning tank decreases, there is acase where the influence of the installation environment temperature andthe difference of the device is received, and it becomes difficult tocontrol the liquid temperature in the cleaning of the nozzle 22 in oneoperation pattern. Therefore, by adjusting the timing of inserting thenozzle 22 into the cleaning liquid and the timing of starting theultrasonic vibration, it is possible to easily perform the control ofincluding the liquid temperature during the cleaning of the nozzle 22 ina desirable range. In other words, the control portion 28 performs theultrasonic cleaning of the nozzle 22 in the certain range of temperaturein the temperature higher than the normal temperature by controlling thedriving timing of the ultrasonic cleaner or the insertion and extractiontiming of the nozzle 22 into and from the cleaning liquid in thecleaning tank.

In addition, in the ultrasonic cleaner 26 of the example, since a highcleaning effect can be obtained during approximately several seconds ofthe cleaning time, the time of giving the ultrasonic vibration isshortened, and further, the cleaning liquid is replaced being overflowedevery time the cleaning is performed. Therefore, even when theultrasonic cleaner 26 is repeatedly used, the ultrasonic cleaner 26itself does not reach the temperature which influences the dispensingaccuracy or the high temperature which causes a damage of the ultrasonicvibrator 2205.

As a method of detecting the liquid temperature, a method of disposingthe temperature sensor (for example, a thermocouple) in the cleaningtank 2206, a method of sticking the temperature sensor (for example, athermocouple) to the cleaning liquid supply tube 2211, or a method ofdisposing an infrared type (non-contact) sensor on the outside of thecleaning tank 2206, is employed, but the temperature detection methoddoes not influence the liquid temperature control method during thenozzle cleaning.

In this manner, when it is possible to detect the liquid temperaturebefore driving the ultrasonic cleaner by the sensor or the like, if arelationship between the driving time of the ultrasonic cleaner and thetemperature increase of the cleaning liquid, for example, which isrepresented by a gradient of the raising temperature per unit time, isknown in advance, the liquid temperature control during the nozzlecleaning can be easily performed. This is because it is possible tocorrectly predict the liquid temperature while the nozzle is in contactwith the cleaning liquid, since it is possible to grasp whether or notthe nozzle is in contact with the cleaning liquid from the loweringamount of the nozzle after several seconds after the device itselfdrives the ultrasonic cleaner.

By adjusting any of the timing (2510) of starting the ultrasonicvibration and the timing (2511) of inserting the nozzle into thecleaning liquid in the cleaning tank, based on the relationship, such asthe temperature gradient of the cleaning liquid investigated in advance,and the liquid temperature before the driving the ultrasonic cleaner, itis possible to set the desirable liquid temperature at the timing (2511)of inserting the nozzle 22 into the cleaning liquid in the cleaningtank. However, in the automatic analyzer, at the timing of the nozzle22, the control which is in synchronization with other units (otherdispensing mechanism or reaction disk) is performed, there is apossibility that the timing adjustment of the driving of the nozzleinfluences other units, and there is a possibility that the controlbecomes complicated. Therefore, it is desirable that the liquidtemperature control during the cleaning is performed at the timing(2510) of starting the ultrasonic vibration.

In addition, the liquid temperature which influences the dispensingaccuracy varies according to the material or the volume of the nozzle22, but it is possible to react to the timing adjustment of the presentinvention by grasping the influence temperature in advance.

In the example, an operation during the operation is described, but evenin a reset operation of initiating the state where the device isinitiated, or in an automatic maintenance operation which is performedwhen finishing the analysis or shutting down the device, it is possibleto increase the temperature of the cleaning liquid, and to perform theeffective cleaning. In this case, the temperature control which does notexcessively increase the liquid temperature is performed by alternatelyperforming the overflow (2501) for replacing the cleaning liquid and thedriving (2502) of the ultrasonic vibrator, or by performing thereplacing (2501) of the cleaning liquid in the middle of performing thedriving (2502) of the ultrasonic vibrator, and it is possible to operatethe ultrasonic cleaner 26 for a long period of time. Similar to thelatter, the cleaning liquid in the cleaning tank is overflowed to theoutside of the cleaning tank, and while performing the control ofguiding new cleaning liquid into the cleaning tank, as the controlportion 28 performs the ultrasonic cleaning of the nozzle, an equivalentcleaning effect is obtained during a short period of time by thealternate performing similar to the former.

In addition, when performing the maintenance operation or the resetoperation of the automatic analyzer, the relationship between thedriving time of the ultrasonic cleaner and the temperature increase ofthe cleaning liquid is stored, and based on the relationship, bycontrolling the driving timing of the ultrasonic cleaner during theoperation or the insertion and extraction timing of the nozzle into andfrom the cleaning liquid in the cleaning tank, it is possible to performthe ultrasonic cleaning of the nozzle within a certain range oftemperature.

In addition, in a case of the reset operation or the maintenanceoperation, unlike a case during the operation, since it is not necessaryto consider the influence on the dispensing accuracy, the temperaturemay be grasped while the ultrasonic vibrator is practically driven bythe above-described sensors or the like, and based on this, thetemperature control may be performed.

FIG. 21 is a configuration example of the dispensing mechanism of theautomatic analyzer and a control block of the cleaner in the presentinvention. On the operation screen of the automatic analyzer 10, adevice operation and display portion 2600, and an analysis performingoperation portion 2601 for performing the examination or a cleaner statedisplay portion 2602 for displaying the state of the ultrasonic cleaner26, are provided. A device control portion 2610 (corresponds to thecontrol portion 28) which controls the device receives the command ofthe device operation and display portion 2600 from an uppercommunication processing portion 2611, and a device sequence processingportion 2612 controls the dispensing mechanism 15 or the ultrasoniccleaner 26 based on sequence data 2613.

A dispensing mechanism control portion 2614 performs the rotation or thevertical operation of the dispensing mechanism 15 via a motor controlportion 2615 and a motor driving portion 2616, and moves the nozzle 22.A cleaner control portion 2617 controls an ultrasonic driving portion(piezoelectric element amplifier) 2619 via an ultrasonic control portion2618, and drives (ON/OFF the ultrasonic wave) the ultrasonic vibrator2205 provided in the ultrasonic cleaner 26.

Since the resonance properties of the ultrasonic vibrator 2205 changesdue to the heat generation, in order to maintain the amplitude generatedin the cleaning head 2209, it is necessary to correct the shift of theresonance frequency. Therefore, the ultrasonic driving portion 2619 usesa frequency adjustment portion (adjustment circuit) 2620, and changesthe driving frequency in accordance with the change in the resonancefrequency.

Furthermore, the cleaner control portion 2617 sends the command to apump control portion 2621, and drives a pump 2630 through which a pumpdriving portion 2622 is linked to the pipe of the cleaning liquid supplytube 2211. A flow path or a tank which mixes pure water and the cleaningliquid with each other is provided on the upstream side of the pump, butis omitted in the example. By sending the cleaning liquid by driving thepump 2630, it is possible to extrude (overflow) the cleaning liquid ofthe cleaning tank 2206 and replace the cleaning liquid.

In addition, a temperature sensor 2640 disposed in the vicinity of thecleaning tank 2206 aggregates values recorded by a temperature meteringportion (temperature sensor value recorder) 2623 by a meteringprocessing portion 2624, accumulates the values in temperature data atthe time of the ultrasonic driving 2625, and records the informationrelated to the relationship between the driving time of the ultrasoniccleaner and the temperature increase of the cleaning liquid, such as thetemperature gradient. By the cleaner control portion 2617, it ispossible to calculate the timing of driving the ultrasonic vibrator 2205based on the temperature data at the time of the ultrasonic driving2625, and to adjust the timing (2510) of starting the ultrasonicvibration. In addition, in a case where the liquid temperature is higherthan a predetermined temperature, it is possible to lower the liquidtemperature by the overflow of the cleaning liquid using the pumpcontrol portion.

The temperature data at the time of the ultrasonic driving 2625 can alsorecord the data at the time of normal operation, determine an abnormalstate of the ultrasonic cleaner 26 by a liquid temperature statemanaging portion 2626, and display the abnormality on the cleaner statedisplay portion 2602. In addition, the cleaner control portion 2614included in the device control portion 2610 performs the control ofreplacing the cleaning liquid in the cleaning tank, and the liquidtemperature state managing portion 2626 included in the device controlportion 2610 can replace the cleaning liquid in the cleaning tank whenit is determined that the measured temperature of the temperaturemetering portion 2623 exceeds a normal range. Since the replacement ofthe cleaning liquid causes the cooling effect, it is possible tosuppress damage of the device caused by the heat. In addition, asdescribed above, the liquid temperature state managing portion 2626 maynotify the abnormality of the ultrasonic cleaner at the same time whenit is determined that the measured temperature of the temperaturemetering portion 2623 exceeds the normal range.

In addition to the above-described methods, the temperature sensor 2640may use any detection means among the detection means for interferingwith the insertion and extraction operation of the nozzle 22,influencing the vibration of the ultrasonic vibrator 2205, orinfluencing the liquid temperature of the cleaning liquid.

FIG. 22 is an example of the cleaning flow in which the ultrasoniccleaner of the example is used. In the cleaning operation of the nozzle22, first, the replacing operation (S2701) of the cleaning liquid isperformed (the operation is not necessary in a case where the cleaningliquid is replaced in advance), it is determined whether or not thereplacement is completed (S2702), and waiting is performed until thefluctuation of the liquid surface is stabilized (S2703). After this, anyof the above-described detection methods with respect to the liquidtemperature of the cleaning liquid in the cleaning tank 2206 is used,the liquid temperature is confirmed (S2704), and the time (timing) atwhich the driving of the ultrasonic vibrator is started is computed(S2705) from the information related to the relationship between thedriving time of the ultrasonic cleaner and the temperature increase ofthe cleaning liquid, such as the temperature gradient of the cleaningliquid which is investigated in advance. After this, waiting isperformed until reaching the computed time without the ultrasonicvibration (S2706), the liquid temperature in the cleaning tank 2206 ismeasured when reaching the computed time (S2707), the driving of theultrasonic vibrator 2205 is started (S2708), and as described above, theprocessing of lowering the nozzle 22 and inserting the nozzle 22 intothe cleaning liquid in the cleaning tank 2206 is performed (S2709), andthe nozzle 22 is drawn out of the cleaning liquid in the cleaning tank2206 after a certain period of time (predetermined cleaning time) haselapsed (S711).

In the driving of the ultrasonic vibrator 2205 (S2708), by performingthe driving using the resonance frequency of the primary vibration modeor the secondary vibration mode of the cleaning head 2209, as describedabove, the heat generation from the neck 2304 of the cleaning head 2209is started, and the temperature of the cleaning liquid in the cleaningtank 2206 can increase. By setting the timing (2510) of starting thedriving of the ultrasonic vibrator 2205 to be an appropriate timing bychecking the start of the ultrasonic vibration (S2706), the liquidtemperature of the cleaning liquid in the cleaning tank 2206 before thenozzle insertion processing (S2709) becomes a value (temperature havinga high cleaning effect) higher than the normal temperature, and thetemperature becomes equal to or lower than the liquid temperature whichdoes not influence the dispensing until performing nozzle drawing-outprocessing (S2711).

After drawing the nozzle 22 out of the cleaning liquid in the cleaningtank 2206, the driving of the ultrasonic vibrator 2205 is stopped(S2712), and the change in the liquid temperature while driving theultrasonic vibrator 2205 is recorded (S2713).

The data, such as the temperature gradient used during the operation,may be updated every time the ultrasonic cleaner 26 is used, or may beobtained during the reset operation at the time of initiating the deviceor the maintenance operation, or by periodically performing theoperations from S2707 to S2713 (S2709 and S2711 related to the nozzleoperation are not necessary). In addition, in a case where the liquidtemperature at every cleaning timing does not change, such as a casewhere the ultrasonic cleaner 26 is used in a certain cycle, by adjustingthe timing by the reset operation or the maintenance operation, thetiming of starting the driving of the ultrasonic vibrator 2205 duringthe operation may be fixed. In addition, in a case where the timing isnot adjusted at the timing of the reset operation or the maintenanceoperation, the driving may be performed at the timing of starting thedriving of the ultrasonic vibrator which is fixed at the time ofshipment. In this case, steps S2705, S2707, and S2713 can be omitted.

In a step of cleaning liquid confirming processing (S2704), in additionto processing of confirming the temperature which influences thedispensing accuracy, or processing of predicting whether or not theliquid temperature becomes the temperature which influences thedispensing accuracy before drawing out the nozzle 22 (S2711) by drivingthe ultrasonic vibrator (S2708), processing of lowering the liquidtemperature by making the cleaning liquid overflowed before driving theultrasonic vibrator (S2708) may be added. However, as described above,since the ultrasonic cleaner 26 reaches the high temperature, and doesnot reach the liquid temperature which influences the dispensingaccuracy in the normal operation, in a case where the temperature higherthan the normal temperature is detected in the cleaning liquidconfirming processing (S2704), processing of displaying an error on theoperating portion of the device may be added.

According to the control method for controlling the liquid temperatureof the ultrasonic cleaner 26 and the cleaning tank 2206 having theabove-described configuration, and generating the cavitation in thecleaning liquid, by controlling the liquid temperature to be in thetemperature range which is higher than the normal temperature and doesnot influence the dispensing accuracy before inserting the nozzle 22into the cleaning tank 2206, and further, focusing the cavitation at thetip end of the cleaning head 2209, it is possible to clean the outercircumference of the nozzle 22 during a short period of time, and toprovide a detection device having high detection accuracy withoutcarrying over another sample which adheres to the nozzle 22.

Among commercial cleaners which vibrate the bottom of the cleaning tankby the piezoelectric element, there is a cleaner which performs thecleaning by generating a flow of the liquid which is called a straightflow in the middle of the liquid by driving the piezoelectric element ata several MHz, and the cleaner is used in cleaning a delicate target(for example, a semiconductor wafer) which does not desire thegeneration of a damage due to the generation of cavitation, but thecleaner is not appropriate since it is difficult to remove thecontaminants which adhere to the nozzle. Meanwhile, the BLT interposesthe piezoelectric element by two metal blocks and drops the resonancefrequency to 20 to 100 kHz, and is advantageous in enlarging theamplitude and generating the cavitation. It is difficult to realize fastdispensing processing when performing the cleaning for a long period oftime in order to increase the cleaning effect, but it is possible toclean the nozzle used in the analyzer which requires fast processingduring a short period of time by using the BLT.

The ultrasonic cleaners of Examples 1 to 5 have common points that thevibration in the horizontal direction is generated in the cleaning tankby the BLT, and the vibrating part which vibrates in the horizontaldirection is provided on the side surface side in the cleaning tank. Inparticular, in the ultrasonic cleaners of Examples 2 to 5, a supportpoint of the vibrating part is provided on the upper part of thecleaning tank, a part thereof is immersed in the cleaning liquid, and itis advantageous in that an amplitude larger than that of a case wherethe diaphragm of Example 1 is used as the vibrating part can beobtained.

In the examples, the sample dispensation of the biochemical automaticanalyzer is described, but the ultrasonic cleaner of the presentinvention can also similarly perform the cleaning in a dispensing nozzleof other clinical examination devices, such as a reagent dispensingnozzle or a dispensing nozzle of an immunological automatic analyzer ora coagulation automatic analyzer. In addition, not being limited to thedispensing nozzle, it is also possible to clean the nozzle whichperforms only the suctioning regardless of the nozzle for suctioning andejecting. The material of the nozzle is not particularly limited, butfor example, a metal nozzle is employed.

In addition, in the above-described embodiments, the analyzer in whichthe measuring portion which performs the photometry with respect to themixture in the reaction cell is provided is described as an example, butin the analyzing method, in addition to the embodiments, the ultrasoniccleaner of the present invention can also be mounted on the analyzerprovided with the measuring portion which is a type of performing thephotometry in the pipe in which the mixture is suctioned from thereaction cell or the like. In addition to the measurement using thelight, the ultrasonic cleaner of the present invention can also bemounted in the analysis in which voltage measurement of the mixture orthe sample is used. Therefore, the measuring portion is not limited tothe photometry. An example of an analyzer which uses the voltagemeasurement of the sample includes an electrolyte measurement device,and the ultrasonic cleaner of the present invention can also be mountedon the electrolyte measurement device.

In other words, a configuration in which the ultrasonic cleaner of thepresent invention is mounted on other clinical examination devices otherthan the biochemical automatic analyzer, is also included in the rangeof the claims of the present invention.

In addition, in Example 5, an example in which the ultrasonic vibratoris driven before inserting the nozzle into the cleaning liquid in thecleaning tank is illustrated, but depending on situation, the ultrasonicvibrator may be driven after the nozzle is inserted into the cleaningliquid.

In addition, the cleaning tank may be included or may not be included inthe configuration of the ultrasonic cleaner.

In addition, similar shape of the vibrating part may be realized in twoor more ultrasonic cleaners. However, as described in theabove-described embodiments, it is possible to reduce the cost byrealizing one ultrasonic cleaner.

In addition, the ultrasonic cleaner described in the embodiments is alsoadvantageous as a single ultrasonic cleaner which cleans the dispensingnozzle or the suctioning nozzle without being combined with theautomatic analyzer.

The above-described embodiments are an example, and various combinationsof the examples are possible. For example, the flow of FIG. 22 may beemployed in the ultrasonic cleaner having the configuration of FIGS. 10to 14, and the flows of FIGS. 8, 15, and 16 may be employed in theultrasonic cleaner having the configuration of FIG. 17 or 18.

In other words, the above-described embodiments are an example, variouscombinations or various modification examples can be considered, andvarious combinations or various modification examples are included inthe range of the claims without departing from the scope of the presentinvention.

REFERENCE SIGNS LIST

-   -   10 AUTOMATIC ANALYZER    -   11 REAGENT CONTAINER    -   12 REAGENT DISK    -   13 REACTION DISK    -   14 REAGENT DISPENSING MECHANISM    -   15 SAMPLE DISPENSING MECHANISM    -   21 REAGENT NOZZLE    -   22 SAMPLE NOZZLE    -   23 SAMPLE CONTAINER    -   24 LACK    -   25 REACTION CELL    -   26 ULTRASONIC CLEANER    -   27 CLEANING TANK    -   28 CONTROL PORTION    -   29 MEASURING PORTION    -   100 BLT    -   200 ULTRASONIC CLEANER    -   201 BLT    -   202 DIAPHRAGM    -   203 CLEANING PORT    -   204 FLANGE    -   205 SEALING MEMBER    -   208 DISCHARGE PORT    -   210 OPENING PART    -   211 CLEANING TANK    -   220 COVER    -   221 PLATE SPRING    -   222 VIBRATING PART    -   223 CLEANER BASE    -   224 BOLT    -   225 LIQUID FEEDING PORT    -   226 HOLE FOR DISCHARGE    -   311 PIEZO ELEMENT    -   312 PRESSING MEMBER    -   313 PRESSING MEMBER    -   321 SCREW PORTION    -   322 METAL PLATE    -   323 VIBRATING PART    -   324 NECK    -   400 VIBRATING PART    -   401 STANDING WAVE    -   402 HALF-WAVELENGTH OF STANDING WAVE    -   403 REGION IN WHICH ULTRASONIC INTENSITY IS STRONG (VIBRATING        PART SIDE)    -   404 REGION IN WHICH ULTRASONIC INTENSITY IS STRONG (LIQUID        SURFACE SIDE)    -   501 RANGE TO WHICH SAMPLE ADHERES    -   502 CLEANING RANGE OF ULTRASONIC CLEANER    -   503 CLEANING RANGE OF WATER CLEANING    -   511 BOTTOM OF CLEANING TANK    -   512 POOL OF CLEANING TANK    -   513 LIQUID LEVEL    -   514 NOZZLE TIP END POSITION    -   515 CENTER LINE OF DIAPHRAGM    -   516 LENGTH FROM FIXING END TO FIXING END OF DIAPHRAGM    -   601 PIPE    -   602 SYRINGE PUMP    -   603 CLEANING LIQUID TANK    -   604 PIPE (FOR WATER WORKS FACILITIES)    -   605 SWITCHING VALVE    -   606 OVERFLOW RECEIVER    -   900 ULTRASONIC CLEANER    -   901 CLEANING PORT    -   902 CLEANING TANK    -   903 SURFACE ON CLEANING TANK SIDE OF CLEANING PORT    -   1200 ULTRASONIC CLEANER    -   1201 ULTRASONIC VIBRATOR    -   1202 VIBRATING PART    -   1203 PLATE SPRING    -   1204 BOLT    -   1205 CLEANER BASE    -   1206 CLEANING TANK    -   1207 SUPPLY PORT    -   1208 DISCHARGE PORT    -   1209 HOLLOW PART    -   1211 METAL BLOCK (ON VIBRATING PART SIDE)    -   1212 METAL BLOCK    -   1213 PIEZO ELEMENT (PIEZOELECTRIC ELEMENT)    -   1300 ULTRASONIC CLEANER    -   1301 ULTRASONIC VIBRATOR    -   1302 VIBRATOR BASE    -   1303 VIBRATING PART    -   1311 METAL BLOCK (ON VIBRATING PART SIDE)    -   1312 METAL BLOCK    -   1313 PIEZO ELEMENT (PIEZOELECTRIC ELEMENT)    -   1314 METAL MEMBER    -   1320 HOLLOW PART    -   1400 ULTRASONIC CLEANER    -   1401 ULTRASONIC VIBRATOR    -   1402 TUBE    -   1403 BOLT (HOLE THROUGH WHICH TUBE PASSES TO INSIDE)    -   1501 PIPE    -   1502 SYRINGE PUMP    -   1503 CLEANING LIQUID TANK    -   1504 PIPE CONNECTED TO WATER WORKS    -   1505 SWITCHING VALVE    -   1506 PIPE CONNECTED TO SEWAGE    -   1507 FLOW PATH OF LIQUID AT TIME OF OVERFLOW    -   2201 FRONT MASS    -   2202 BACK MASS    -   2203 PIEZOELECTRIC ELEMENT    -   2204 BOLT    -   2205 ULTRASONIC VIBRATOR    -   2206 CLEANING TANK    -   2207 BASE PORTION    -   2208 FLANGE PORTION    -   2209 VIBRATING PART (CLEANING HEAD)    -   2210 TIP END PART    -   2211 CLEANING LIQUID SUPPLY TUBE    -   2212 LIQUID RECEIVER    -   2213 DRAINAGE PATH    -   2301 FIXING PORTION    -   2302 CLEANING PORTION    -   2303 HOLLOW PART (NOZZLE INSERTION PORT)    -   2304 NECK    -   2305 REINFORCING PORTION    -   2311 RECTANGULAR BLOCK SHAPE    -   2312 CYLINDRICAL SHAPE    -   2313 SHAPE IN WHICH PRISMATIC HOLE IS OPEN    -   2314 CLEANING HEAD    -   2401 TEMPERATURE GRADIENT    -   2402 LINEAR APPROXIMATE LINE    -   2501 OVERFLOW OPERATION    -   2502 DRIVING OPERATION OF ULTRASONIC VIBRATOR    -   2503 OPERATION OF INSERTING NOZZLE INTO CLEANING LIQUID IN        CLEANING TANK    -   2504 OPERATION OF DRAWING NOZZLE OUT OF CLEANING LIQUID IN        CLEANING TANK    -   2505 OPERATION OF STOPPING DRIVING OF ULTRASONIC VIBRATOR    -   2506 OVERFLOW OPERATION    -   2510 TIMING OF STARTING DRIVING OF ULTRASONIC VIBRATOR    -   2511 TIMING OF INSERTING NOZZLE INTO CLEANING LIQUID INTO        CLEANING TANK    -   2512 TIMING OF DRAWING NOZZLE OUT OF CLEANING LIQUID IN CLEANING        TANK    -   2513 TIMING OF STOPPING ULTRASONIC VIBRATOR    -   2520 TEMPERATURE OF CLEANING LIQUID    -   2600 DEVICE OPERATION AND DISPLAY PORTION    -   2601 ANALYSIS PERFORMING OPERATION PORTION    -   2602 CLEANER STATE DISPLAY PORTION    -   2610 DEVICE CONTROL PORTION    -   2611 UPPER COMMUNICATION PROCESSING PORTION    -   2612 DEVICE SEQUENCE PROCESSING PORTION    -   2613 SEQUENCE DATA    -   2614 DISPENSING MECHANISM CONTROL PORTION    -   2615 MOTOR CONTROL PORTION    -   2616 MOTOR DRIVING PORTION    -   2617 CLEANER CONTROL PORTION    -   2618 ULTRASONIC CONTROL PORTION    -   2619 ULTRASONIC DRIVING PORTION    -   2620 FREQUENCY ADJUSTMENT PORTION    -   2621 PUMP CONTROL PORTION    -   2622 PUMP DRIVING PORTION    -   2623 TEMPERATURE METERING PORTION    -   2624 METERING PROCESSING PORTION    -   2625 TEMPERATURE DATA AT TIME OF ULTRASONIC DRIVING    -   2626 LIQUID TEMPERATURE STATE MANAGING PORTION    -   2630 PUMP    -   2640 TEMPERATURE SENSOR

The invention claimed is:
 1. An ultrasonic cleaner comprising: avibrating part which is inserted into cleaning liquid in a cleaning tankand transmits ultrasonic vibration to the cleaning liquid; an ultrasonicvibrator which generates the ultrasonic vibration to the vibrating part;and a control portion which performs driving control of the ultrasonicvibrator, wherein one portion of the vibrating part is connected to theultrasonic vibrator at an upper part of the cleaning tank, wherein apart provided at another portion of the vibrating part vibrates as afree end in accordance with vibration of the ultrasonic vibrator, andwherein the control portion causes the vibrating part to generate theultrasonic vibration, to clean a nozzle.
 2. The ultrasonic cleaneraccording to claim 1, wherein the vibrating part is provided with twosurfaces that oppose each other via a hollow part.
 3. The ultrasoniccleaner according to claim 1, wherein the vibrating part has a resonancepoint at which the vibrating part inserted into the cleaning tankresonates and vibrates within a range of 20 to 100 kHz when theultrasonic vibrator vibrates, and wherein the control portion causes thevibrating part to vibrate at 20 to 100 kHz in a state where the nozzleis inserted into a hollow part, to clean the nozzle.
 4. The ultrasoniccleaner according to claim 3, wherein the vibrating part has a resonancepoint at which the vibrating part resonates and vibrates in a secondaryvibration mode within a range of 20 to 100 kHz, and wherein the controlportion causes the ultrasonic vibrator to vibrate at a frequency atwhich the vibrating part vibrates in the secondary vibration mode toclean the nozzle.
 5. The ultrasonic cleaner according to claim 1,wherein the vibrating part is connected to one of a plurality of metalblocks, and wherein the one metal block to which the vibrating part isconnected, has a shape of a horn whose diameter continuously decreaseswhen approaching the vibrating part.
 6. The ultrasonic cleaner accordingto claim 1, wherein the vibrating part includes a member extending in aperpendicular direction, wherein a cleaning portion is provided at a tipend of the member, and wherein a connection portion for separating thehollow part and the member is provided between the cleaning portion andthe member.
 7. The ultrasonic cleaner according to claim 6, wherein theconnection portion has a round part.
 8. The ultrasonic cleaner accordingto claim 1, wherein an absolute value of a difference between aresonance point of the ultrasonic vibrator and a resonance point of thevibrating part is equal to or less than 10 kHz.
 9. The ultrasoniccleaner according to claim 1, wherein the vibrating part has a hollowpart filled with cleaning liquid into which the nozzle for suctioning asample or a reagent is inserted.
 10. The ultrasonic cleaner according toclaim 1, wherein the ultrasonic vibrator is configured by fixing apiezoelectric element with two or more metal blocks by a fastener, andwherein the ultrasonic vibrator generates the ultrasonic vibration tothe vibrating part in a horizontal direction.
 11. The ultrasonic cleaneraccording to claim 9, wherein the control portion causes the vibratingpart to generate the ultrasonic vibration in a state where the nozzle isinserted into a hollow part.
 12. An ultrasonic cleaner comprising: avibrating part which is inserted into cleaning liquid in a cleaning tankand transmits ultrasonic vibration to the cleaning liquid; an ultrasonicvibrator which generates the ultrasonic vibration to the vibrating part;and a control portion which performs driving control of the ultrasonicvibrator, wherein one portion of the vibrating part is connected to theultrasonic vibrator at an upper part of the cleaning tank, wherein apart provided at another portion of the vibrating part vibrates as afree end in accordance with vibration of the ultrasonic vibrator, andwherein the control portion causes the vibrating part to generate theultrasonic vibration, to clean a nozzle, wherein the ultrasonic vibratoris configured by fixing a piezoelectric element with two or more metalblocks by a fastener, and wherein the ultrasonic vibrator generates theultrasonic vibration to the vibrating part in a horizontal direction.13. An ultrasonic cleaner comprising: a vibrating part which is insertedinto cleaning liquid in a cleaning tank and transmits ultrasonicvibration to the cleaning liquid; an ultrasonic vibrator which generatesthe ultrasonic vibration to the vibrating part; and a control portionwhich performs driving control of the ultrasonic vibrator, wherein oneportion of the vibrating part is connected to the ultrasonic vibrator atan upper part of the cleaning tank, wherein a part provided at anotherportion of the vibrating part vibrates as a free end in accordance withvibration of the ultrasonic vibrator and provided with surfaces opposingeach other, and wherein the control portion causes a nozzle to beinserted between the surfaces and the vibrating part to generate theultrasonic vibration, to clean the nozzle.
 14. The ultrasonic cleaneraccording to claim 13, wherein the ultrasonic vibrator is configured byfixing a piezoelectric element with two or more metal blocks by afastener, and wherein the ultrasonic vibrator generates the ultrasonicvibration to the vibrating part in a horizontal direction.